Archive for the ‘Baserunning’ Category

With all the hullaballoo about Utley’s slide last night and the umpires’ calls or non-calls, including the one or ones in NY (whose names, addresses, telephone numbers, and social security numbers should be posted on the internet, according to Pedro Martinez), what was lost – or at least there was much confusion – was a discussion of the specific rule(s) that applies to that exact situation – the take-out slide that is, not whether Utley was safe or not on replay. For that you need to download the 2015 complete rule book, I guess. If you Google certain rule numbers, it takes you to the MLB “official rules” portion of their website in which at least some of the rule numbers appear to be completely different than in the actual current rule book.

In any case, last night after a flurry of tweets, Rob Neyer, from Fox Sports, pointed out the clearly applicable rule (although other rules come close): It is 5.09 (a) (13) in the PDF version of the current rulebook. It reads, in full:

The batter is out when… “A preceding runner shall, in the umpire’s judgment, intentionally interfere with a fielder who is attempting to catch a thrown ball or to throw a ball in an attempt to complete any play;”

That rule is unambiguous and crystal clear. 1) Umpire, in his judgment, determines that runner intentionally interferes with the pivot man. 2) The batter must be called out.

By the way, the runner himself may or may not be out. This rule does not address that. There is a somewhat common misperception that the umpire calls both players out according to this rule. Another rule might require the umpire to call the runner also out on interference even if he arrived before the ball/fielder or the fielder missed the bag – but that’s another story.

Keep in mind that if you ask the umpire, “Excuse me, Mr. umpire, but in your judgment, did you think that the runner intentionally interfered with the fielder,” and his answer is, “Yes,” then he must call the batter out. There is no more judgment. The only judgment allowed in this rule is whether the runner intentionally interfered or not. If the rule had said, “The runner may be called out,” then there would be two levels of judgment, presumably. There are other rules which explicitly say the umpire may do certain things, in which case there is presumably some judgement that goes into whether he decides to do them or not. Sometimes those rules provide guidelines for that judgment (the may part) and sometimes they do not. Anyway, this rule does not provide that may judgment. If umpire thinks is it intentional interference, the batter (not runner) is automatically out.

So clearly the umpire should have called the batter out on that play, unless he could say with a straight face, “In my judgment, I don’t think that Utley intentionally interfered with the fielder.” That is not a reasonable judgment of course. Not that there is much recourse for poor or even terrible judgment. Judgment calls are not reviewable, I don’t think. Perhaps umpires can get together and overturn a poor judgment call. I don’t know.

But that’s not the end of the story. There is a comment to this rule which reads:

“Rule 5.09(a)(13) Comment (Rule 6.05(m) Comment): The objective of this rule is to penalize the offensive team for deliberate, unwarranted, unsportsmanlike action by the runner in leaving the baseline for the obvious purpose of crashing the pivot man on a double play, rather than trying to reach the base. Obviously this is an umpire’s judgment play.”

Now that throws a monkey wrench into this situation. Apparently this is where the (I always thought it was an unwritten rule), “Runner must be so far away from the base that he cannot touch it in order for the ‘automatic double play’ to be called” rule came from. Only it’s not a rule. It is a comment which clearly adds a wrinkle to the rule.

The rule is unambiguous. If the runner interferes with the fielder trying to make the play (whether he would have completed the DP or not), then the batter is out. There is no mention of where the runner has to be or not be. The comment changes the rule. It adds another requirement (and another level of judgment). The runner must have been “outside the baseline” in the umpire’s judgment. In addition, it adds some vague requirements about the action of the runner. The original rule says only that the runner must “intentionally interfere” with the fielder. The comment adds words that require the runner’s actions to be more egregious – deliberate, unwarranted, and unsportsmanlike.

But the comment doesn’t really require that to be the case for the umpire to call the batter out. I don’t think. It says, “The objective of this rule is to penalize the offensive team….” I guess if the comment is meant to clarify the rule, MLB really doesn’t want the umpire to call the batter out unless the requirements in the comment are met (runner out of the baseline and his action was not only intentional but deliberate, unwarranted, and unsportsmanlike, a higher bar than just intentional).

Of course the rule doesn’t need clarification. It is crystal clear. If MLB wanted to make sure that the runner is outside of the baseline and acts more egregiously than just intentionally, then they should change the rule, right? Especially if comments are not binding, which I presume they are not.

Also, the comment starts off with: “The objective of this rule is to…”

Does that mean that this rule is only to be applied in double play situations? What if a fielder at second base fields a ball, starts to throw to first base to retire the batter, and the runner tackles him or steps in front of the ball? Is rule 5.09(a)(13) meant to apply? The comment says that the objective of the rule is to penalize the offensive team for trying to break up the double play. In this hypothetical, there is no double play being attempted. There has to be some rule that applies to this situation? If there isn’t, then MLB should not have written in the comment, “The objective of this rule….”

There is another rule which also appears to clearly apply to a take-out slide at second base, like Utley’s, with no added comments requiring that the runner be out of the baseline, or that his actions be unwarranted and unsportsmanlike. It is 6.01(6). Or 7.09(e) on the MLB web site. In fact, I tweeted this rule last night thinking that it addressed the Utley play 100% and that the runner and the batter should have been called out.

“If, in the judgment of the umpire, a base runner willfully and deliberately interferes with a batted ball or a fielder in the act of fielding a batted ball with the obvious intent to break up a double play, the ball is dead. The umpire shall call the runner out for interference and also call out the batter-runner because of the action of his teammate.”

The only problem there are the words, “interferes with a batted ball or a fielder in the act of fielding a batted ball.” A lawyer would say that the plain meaning of the words precludes this from applying to an attempt to interfere with a middle infielder tagging second base and throwing to first, because he is not fielding or attempting to field a batted ball and the runner is not interfering with a batted ball. The runner, in this case, is interfering with a thrown ball or a fielder attempting to tag second and then make a throw to first.

So if this rule is not meant to apply to a take-out slide at second, what is it meant to apply to? That would leave only one thing really. A ground ball is hit in the vicinity of the runner and he interferes with the ball or a fielder trying to field the ball. But there also must be, “an obvious intent to break up a double play.” That is curious wording. Would a reasonable person consider that an attempt to break up a double play? Perhaps ”obvious intent to prevent a double play.” Using the words break up sure sounds like this rule is meant to apply to a runner trying to take out the pivot man on a potential double play. But then why write “fielding a batted ball” rather than “making a play or a throw?”

A good lawyer working for the Mets would try and make the case that “fielding a batted ball” includes everything that happens after someone actually “fields the batted ball,” including catching and throwing it. In order to do so, he would probably need to find that kind of definition somewhere else in the rule book. It is a stretch, but it is not unreasonable, I don’t think.

Finally, Eric Byrnes on MLB Tonight, had one of the more intelligent and reasonable comments regarding this play that I have ever heard from an ex-player. He said, and I paraphrase:

“Of course it was a dirty slide. But all players are taught to do whatever it takes to break up the DP, especially in a post-season game. Until umpires start calling an automatic double play on slides like that, aggressive players like Utley will continue to do that. I think we’ll see a change soon.”

P.S. For the record, since there was judgment involved, and judgment is supposed to represent fairness and common sense, I think that Utley should not have been ruled safe at second on appeal.


Perhaps comments are binding. From the forward to the rules, on the MLB web site:

The Playing Rules Committee, at its December 1977 meeting, voted to incorporate the Notes/Case Book/Comments section directly into the Official Baseball Rules at the appropriate places. Basically, the Case Book interprets or elaborates on the basic rules and in essence have the same effect as rules when applied to particular sections for which they are intended.


There is a prolific base stealer on first base in a tight game. The pitcher steps off the rubber, varies his timing, or throws over to first several times during the AB. You’ve no doubt heard some version of the following refrain from your favorite media commentator: “The runner is disrupting the defense and the pitcher, and the latter has to throw more fastballs and perhaps speed up his delivery or use a slide step, thus giving the batter an advantage.”

There may be another side of the same coin: The batter is distracted by all these ministrations, he may even be distracted if and when the batter takes off for second, and he may take a pitch that he would ordinarily swing at in order to let the runner steal a base. All of this leads to decreased production from the batter, as compared to a proverbial statue on first, to which the defense and the pitcher pay little attention.

So what is the actual net effect? Is it in favor of the batter, as the commentators would have you believe (after all, they’ve played the game and you haven’t), or does it benefit the pitcher – an unintended negative consequence of being a frequent base stealer?

Now, even if the net effect of a stolen base threat is negative for the batter, that doesn’t mean that being a prolific base stealer is necessarily a bad thing. Attempting stolen bases, given a high enough success rate, presumably provides extra value to the offense independent of the effect on the batter. If that extra value exceeds that given up by virtue of the batter being distracted, then being a good and prolific base stealer may be a good thing. If the pundits are correct and the “net value of distraction” is in favor of the batter, then perhaps the stolen base or stolen base attempt is implicitly worth more than we think.

Let’s not also forget that the stolen base attempt, independent of the success rate, is surely a net positive for the offense, not withstanding any potential distraction effects. That is due to the fact that when the batter puts the ball in play, whether it is a hit and run or a straight steal, there are fewer forces at second, fewer GDP’s, and the runner advances the extra base more often on a single, double, or out. Granted, there are a few extra line drive and fly ball DP, but there are many fewer GDP to offset those.

If you’ve already gotten the feeling that this whole steal thing is a lot more complicated than it appears on its face, you would be right. It is also not easy, to say the least, to try and ascertain whether there is a distraction effect and who gets the benefit, the offense or the defense. You might think, “Let’s just look at batter performance with a disruptive runner on first as compared to a non-disruptive runner.” We can even use a “delta,” “matched pairs,” or “WOWY” approach in order control for the batter, and perhaps even the pitcher and other pertinent variables. For example, with Cabrera at the plate, we can look at his wOBA with a base stealing threat on first and a non-base stealing threat. We can take the difference, say 10 points in wOBA in favor of with the threat (IOW, the defense is distracted and not the batter), and weight that by the number of times we find a matched pair (the lesser of the two PA). In other words, a “matched pair” is one PA with a stolen base threat on first and one PA with a non-threat.

If Cabrera had 10 PA with a stolen base threat and 8 PA with someone else on first, we would weight the wOBA difference by 8 – we have 8 matched pairs. We do that for all the batters, weighting each batter’s difference by their number of matched pairs, and voila, we have a measure of the amount that a stolen base threat on first affects the batter’s production, as compared to a non-stolen base threat. Seems pretty simple and effective, right? Eh, not so fast.

Unfortunately there are myriad problems associated with that methodology. First of all, do we use all PA where the runner started on first but may have ended up on another base, or was thrown out, by the time the batter completed his PA? If we do that, we will be comparing apples to oranges. With the base stealing threats, there will be many more PA with a runner on second or third, or with no runners at all (on a CS or PO). And we know that wOBA goes down once we remove a runner from first base, because we are eliminating the first base “hole” with the runner being held on. We also know that the value of the offensive components are different depending on the runners and outs. For example, with a runner on second, the walk is not as valuable to the batter and the K is worse than a batted ball out which has a chance to advance the runner.

What if we only look at PA where the runner was still at first when the batter completed his PA? Several researchers have done that, included myself and my co-authors in The Book. The problem with that method is that those PA are not an unbiased sample. For the non-base stealers, most PA will end with a runner on first, so that is not a problem. But with a stolen base threat on first, if we only include those PA that end with the runner still on first, we are only including PA that are likely biased in terms of count, score, game situation, and even the pitcher. In other words, we are only including PA where the runner has not attempted a steal yet (other than on a foul ball). That could mean that the pitcher is difficult to steal on (many of these PA will be with a LHP on the mound), the score is lopsided, the count is biased one way or another, etc. Again, if we only look at times where the PA ended with the runner on first, we are comparing apples to oranges when looking at the difference in wOBA between a stolen base threat on first and a statue.

It almost seems like we are at an impasse and there is nothing we can do, unless perhaps we try to control for everything, including the count, which would be quite an endeavor. Fortunately there is a way to solve this – or at least come close. We can first figure out the overall difference in value to the offense between having a base stealer and a non-base stealer on first, including the actual stolen base attempts. How can we do that? That is actually quite simple. We need only look at the change in run expectancy starting from the beginning to the end of the PA, starting with a runner on first base only. We can then use the delta or matched pairs method to come up with an average difference in change in RE. This difference represents the sum total of the value of a base stealer at first versus a non-base stealer, including any effect, positive or negative, on the batter.

From there we can try and back out the value of the stolen bases and caught stealings (including pick-offs, balks, pick-off errors, catcher errors on the throw, etc.) as well as the extra base runner advances and the avoidance of the GDP when the ball is put into play. What is left is any “distraction effect” whether it be in favor of the batter or the pitcher.

First, in order to classify the base runners, I looked at their number of steal attempts per times on first (BB+HP+S+ROE) for that year and the year before. If it was greater than 20%, they were classified as a “stolen-base threat.” If it was less than 2%, they were classified as a statue. Those were the two groups I looked at vis-à-vis the runner on first base. All other runners (the ones in the middle) were ignored. Around 10% of all runners were in the SB threat group and around 50% were in the rarely steal group.

Then I looked at all situations starting with a runner on first (in one or the other stolen base group) and ending when the batter completes his PA or the runner makes the third out of the inning. The batter may have completed his PA with the runner still on first, on second or third, or with no one on base because the runner was thrown out or scored, via stolen bases, errors, balks, wild pitches, passed balls, etc.

I only included innings 1-6 (to try and eliminate pinch runners, elite relievers, late and close-game strategies, etc.) and batters who occupied the 1-7 slots. I created matched pairs for each batter such that I could use the “delta method” described above to compute the average difference in RE change. I did it year by year, i.e., the matched pairs had to be in the same year, but I included 20 years of data, from 1994-2013. The batters in each matched pair had to be on the same team as well as the same year. For example, Cabrera’s matched pairs of 8 PA with base stealers and 10 PA with non-base stealers would be in one season only. In another season, he would have another set of matched pairs.

Here is how it works: Batter A may have had 3 PA with a base stealer on first and 5 with a statue. His average change in RE (everyone starts with a runner on first only) at the end of the PA may have been +.130 runs for those 3 PA with the stolen base threat on first at the beginning of the PA.

For the 5 PA with a non-threat on first, his average change in RE may have been .110 runs. The difference is .02 runs in favor of the stolen base on first and that gets weighed by 3 PA (the lesser of the 5 and the 3 PA). We do the same thing for the next batter. He may have had a difference of -.01 runs (in favor of the non-threat) weighted by, say, 2 PA. So now we have (.02 * 3 – .01 * 2) / 5 as our total average difference in RE change using the matched pair or delta method. Presumably (hopefully) the pitcher, score, parks, etc. are the same or very similar for both groups. If they are, then that final difference represents the advantage of having a stolen base threat on first base, including the stolen base attempts themselves.

A plus number means a total net advantage to the offense with a prolific base stealer on first, including his SB, CS, and speed on the bases when the ball is put into play, and a negative number means that the offense is better off with a slow, non-base stealer on first, which is unlikely of course. Let’s see what the initial numbers tell us. By the way, for the changes in RE, I am using Tango’s 1969-1992 RE matrix from this web site:

We’ll start the analysis with no out situations. One of the advantages of a base stealer on first is staying out of the GDP (again, offset by a few extra line drive and fly ball DP). There were a total of 5,065 matched pair PA (adding the lesser of the two PA for each matched pair). Remember a matched pair is a certain batter with a base stealing threat on first and that same batter in the same year with a non-threat on first. The runners are on first base when the batter steps up to the plate but may not be when the PA is completed. That way we are capturing the run expectancy change of the entire PA, regardless of what happens to the runner during the PA.

The average advantage in RE change (again, that is the ending RE after the PA is over minus the starting RE, which is always with a runner on first only, in this case with 0 out) was .032 runs per PA. So, as we expect, a base stealing threat on first confers an overall advantage to the offensive team, at least with no outs. This includes the net run expectancy of SB (including balks, errors, etc.) and CS (including pick-offs), advancing on WP and PB, advancing on balls in play, staying out of the GDP, etc., as well as any advantage or disadvantage to the batter by virtue of the “distraction effect.”

The average wOBA of the batter, for all PA, whether the runner advanced a base or was thrown out during the PA, was .365 with a non-base stealer on first and .368 for a base stealer.

What are the differences in individual offensive components between a base stealing threat and a non-threat originally on first base? The batter with a statue who starts on first base has a few more singles, which is expected given that he hits with a runner on first more often. As well, the batter with a base stealing threat walks and strikes out a lot more, due to the fact he is hitting with a base open more often.

If we then compute the RE value of SB, CS (and balks, pickoffs, errors, etc.) for the base stealer and non-base stealer, as well as the RE value of advancing the extra base and staying out of the DP, we get an advantage to the offense with a base stealer on first of .034 runs per PA.

So, if the overall value of having a base stealer on first is .032 runs per PA, and we compute that .034 runs comes from greater and more efficient stolen bases and runner advances, we must conclude that that there is a .002 runs disadvantage to the batter when there is a stolen base threat on first base. That corresponds to around 2 points in wOBA. So we can say that with no outs, there is a 2 point penalty that the batter pays when there is a prolific base stealer on first base, as compared to a runner who rarely attempts a SB. In 5065 matched PA, one SD of the difference between a threat and non-threat is around 10 points in wOBA, so we have to conclude that there is likely no influence on the batter.

Let’s do the same exercise with 1 and then 2 outs.

With 1 out, in 3,485 matched pair, batters with non-threats hit .388 and batters with threats hit .367. The former had many more singles and of course fewer BB (a lot fewer) and K. Overall, with a non-base stealer starting on first base at the beginning of the PA, batters produced an RE that was .002 runs per PA better than with a base stealing threat. In other words, having a prolific, and presumably very fast, base stealer on first base offered no overall advantage to the offensive team, including the value of the SB, base runner advances, and avoiding the GDP.

If we compute the value that the stolen base threats provide on the base paths, we get .019 runs per PA, so the disadvantage to the batter by virtue of having a prolific base stealer on first base is .021 runs per PA, which is the equivalent of the batter losing 24 points in wOBA.

What about with 2 outs? With 2 outs, we can ignore the GDP advantage for the base stealer as well as the extra value from moving up a base on an out. So, once we get the average RE advantage for a base stealing threat, we can more easily factor out the stolen base and base running advantage to arrive at the net advantage or disadvantage to the batter himself.

With 2 outs, the average RE advantage with a base stealer on first (again, as compared to a non-base stealer) is .050 runs per PA, in a total of 2,390 matched pair PA. Here, the batter has a wOBA of .350 with a non-base stealer on first, and .345 with a base stealer. There is a still a difference in the number of singles because of the extra hole with the first baseman holding on the runner, as well as the usual greater rate of BB with a prolific stealer on base. (Interestingly, with 2 outs, the batter has a higher K rate with a non-threat on base – it is usually the opposite.) Let’s again tease out the advantage due to the actual SB/CS and base running and see what we’re left with. Here, you can see how I did the calculations.

With the non-base stealer, the runner on first is out before the PA is completed 1.3% of the time, he advances to second, 4.4% of the time, and to third, .2%. The total RE change for all that is .013 * -.216 + .044 * .109 + .002 * .157, or .0023 runs, not considering the count when these events occurred. The minus .216, plus .109, and plus .157 are the change in RE when a base runner is eliminated from first, advances from first to second, and advances from first to third prior to the end of the PA (technically prior to the beginning of the PA). The .013, .044, and .002 are the frequencies of those base running events.

For the base stealer, we have .085 (thrown out) times -.216 + .199 (advance to 2nd) * .109 + .025 (advance to 3rd) * .157, or .0117. So the net advantage to the base stealer from advancing or being thrown is .0117 minus .0023, or .014 runs per PA.

What about the advantage to the prolific and presumably fast base stealers from advancing on hits? The above .014 runs was from advances prior to the completion of the PA, from SB, CS, pick-offs, balks, errors, WP, and PB.

The base stealer advances the extra base from first on a single 13.5% more often and 21.7% more often on a double. Part of that is from being on the move and part of that is from being faster.

12.5% of the time, there is a single with a base stealing threat on first. He advances the extra base 13.5% more often, but the extra base with 2 outs is only worth .04 runs, so the gain is negligible (.0007 runs).

A runner on second and a single occurs 2.8% of the time with a stolen base threat on base. The base stealer advances the extra base and scores 14.6% more often than the non-threat for a gain of .73 runs (being able to score from second on a 2-out single is extremely valuable), for a total gain of .73 * .028 * .146, or .003 runs.

With a runner on first and a double, the base stealer gains an extra .0056 runs.

So, the total base running advantage when the runner on first is a stolen base threat is .00925 runs per PA. Add that to the SB/CS advantage of .014 runs, and we get a grand total of .023 runs.

Remember that the overall RE advantage was .050 runs, so if we subtract out the base runner advantage, we get a presumed advantage to the batter of .050 – .023, or .027 runs per PA. That is around 31 points in wOBA.

So let’s recap what we found. For each of no outs, 1 out, and 2 outs, we computed the average change in RE for every batter with a base stealer on first (at the beginning of the PA) and a non-base stealer on first. That tells us the value of the PA from the batter and the base runner combined. (That is RE24, by the way.) We expect that this number will be higher with base stealers, otherwise what is the point of being a base stealer in the first place if you are not giving your team an advantage?

Table I – Overall net value of having a prolific and disruptive base stealing threat on first base at the beginning of the PA, the value of his base stealing and base running, and the presumed value to the batter in terms of any “distraction effect.” Plus is good for the offense and minus good for the defense.

Outs Overall net value SB and base running value “Batter distraction” value
0 .032 runs (per PA) .034 runs -.002 runs (-2 points of wOBA)
1 -.002 runs .019 -.21 runs (-24 pts)
2 .050 runs .023 + .027 (31 pts)


We found that very much to be the case with no outs and with 2 outs, but not with 1 out. With no outs, the effect of a prolific base runner on first was .032 runs per PA, the equivalent of raising the batter’s wOBA by 37 points, and with 2 outs, the overall effect was .050 runs, the equivalent of an extra 57 points for the batter. With 1 out, however, the prolific base stealer is in effect lowering the wOBA of the batter by 2 points. Remember that these numbers include the base running and base stealing value of the runner as well as any “distraction effect” that a base stealer might have on the batter, positive or negative. In other words, RE24 captures the influence of the batter as well as the base runners.

In order to estimate the effect on the batter component, we can “back out” the base running value by looking at how often the various base running events occur and their value in terms of the “before and after” RE change. When we do that, we find that with 0 outs there is no effect on the batter from a prolific base stealer starting on first base. With 1 out, there is a 24 point wOBA disadvantage to the batter, and with 2 outs, there is a 31 point advantage to the batter. Overall, that leaves around a 3 or 4 point negative effect on the batter. Given the relatively small sample sizes of this study, one would not want to reject the hypothesis that having a prolific base stealer on first base has no net effect on the batter’s performance. Why the effect depends so much on the number of outs, and what if anything managers and players can do to mitigate or eliminate these effects, I will leave for the reader to ponder.


We all know the obvious results. He is safe and the RE or WE (we’ll only talk about run expectancy from now on) changes to reflect a runner on second rather than first (although now we are in middle of a PA, so it is not quite so simple). Or he is out and the RE reflects a base runner removed, although again, we are in the middle of the PA with some kind of a ball and strike count.

But, what happens when the base runner is attempting a steal and the batter puts the ball in play? That is the hidden value (presumably) of stolen base attempts, not withstanding the effect it might have on the pitcher and the defense, as per conventional wisdom. I will look into that in Part II.

Where does that extra value come from? In the extra bases that the runner takes on a single or double, staying out of the GDP, removing the force play even when a GDP was not in order (but the force still was), and occasionally forcing a FC no out (when they tried to get the force on the runner at second and he was safe) or a hit, when the only play would have been a force at second had the runner not been in motion. The one downside is the occasional DP on a line drive or short fly ball.

Unfortunately, there is no database that I have access to that tells me whether a runner was in motion or not. I don’t know why. This is a basic piece of information that is necessary for all kinds of important research. I am pretty sure that most of the database companies track this information (it is certainly easy to do so – just one more click of the mouse on occasion), but for some reason they don’t include it in the information that is available to me, and that includes retrosheet.

So, I had to figure out a way to infer when a runner might be running and the batter puts the ball in play. Here is how I did that:

First, I looked only at base runners on first that had a high stolen base attempt per opportunity for that year (.20 per opp or higher). Then I split the pitchers into 2 categories – those who allow very few stolen base attempts per 9 innings (<.35) and those that allowed quite a bit (> 1.80). The assumption is that even these high frequency base stealers would attempt a stolen base much less often against the first group of pitchers than against the second group. I also only included RH pitchers, otherwise the “low attempt pitchers” would contain too many lefties and the batted ball results would be biased.

I only looked at situations where there was a runner on first base, and no other base runners.

What we want to look at is the rate that all that good stuff I mentioned above happens when the runner at first is either likely to be running on the pitch or not.

So let’s look at some data.

Remember that all of the data are with high frequency base stealers (HFBS) on first base, and no runners on second or third. A high frequency base stealer is any player who had at least 50 base stealing opportunities (runner on first, no one on second) and a 20% attempt rate, in that season.

Then I looked at what happened with those runners on base with two groups of RH pitchers on the mound – one, those that allowed very few SB attempts (less than .35 per 9 innings) and those that allowed a lot (> 1.8 per 9). The presumption is that against the first group even these prolific base stealers attempted a SB infrequently, and against the second group they ran a lot. This assumption turned out to be true.

Table I: SB attempt rates (among prolific base stealers), when on first base and no one else on base.

Against low frequency pitchers (Group I) Against high frequency pitchers (Group II)
7.6% 41.3%

That is a lot of base stealing against the second group of pitchers! These are attempts that resulted in a SB or CS only. They don’t include pickoffs, balks, etc.

These numbers do not include when the runner was in motion and the batter put the ball into play. That number has to be inferred. You will see in a second how I did that.

Now let’s look at the GDP and Force out (and FC) rates when the batter hit a ground ball with less than 2 outs.  Presumably, some percentage of the time these high frequency base stealers were running on the pitch and the ball was put into play (therefore no SB or CS was recorded). We can assume that they did so much more frequently against the Group II pitchers than against Group I pitchers since the SB attempt rate was so much higher against Group II than Group I.  In situations where the runner attempt to steal a lot, he will also necessarily be in motion quite often when the ball is put into play. If in a certain situation there are very few steal attempts, then the runner will likely not be running much on a ball in play.

Table II: GDP and Force out (and FC) percentages against Group I and II pitchers

Against low frequency pitchers (Group I) Against high frequency pitchers (Group II)
Batter hits a ground ball out or FC w/ runner on first, less than 2 outs 12.3% 12.8%
GDP 39.3% 30.6%
Force out at second, batter safe 20.9% 21.7%
Fielder’s Choice, no out .5% .6%
Runner safe at second, batter out 38.3% 47.2%

From these numbers, we can infer, at least approximately, how often the runner at first is running on the pitch (attempting to steal or perhaps a hit and run).

Against Group I pitchers, the runner is out at second (via a force or a GDP) 60.2% of the time. With Group II pitchers on the mound, they are out at second only 52.3% of the time. That suggests that at least 7.9% of the time that a ground ball out is made, the runner at first is on the move. I say, “At least,” because some small percentage of time the runner is on the move against Group I pitchers as well (remember they still allow a 7.6% SB attempt rate) and occasionally when a runner on first is off with the pitch, he is still forced at second (e.g., on a hard hit ball right near the bag).

So let’s do some fairly simple algebra. If the SB attempt rate against Group I pitchers is 8%, and 41% against Group II pitches, we have this equation:

.41 * P  – .08 * P = .08

where P is the ratio of runners on the move when the ball is in play to runner on the move when the ball is not in play (an actual SB attempt). Solving for P, we get .24. That means that for every SB attempt by a base runner, there is an addition .24 times when the batter puts the ball in play and the runner is on the move. This creates an advantage for the batting team by staying out the DP and rarely being forced at second, and advancing the extra base more often on a single or double.

By the way, the percentage of fly ball or line drive double plays for both groups was almost the same: 1.5% when running a lot (against Group II pitchers) and .9% when not running a lot. While that suggests that the runner in motion gets doubled up slightly more often than the runner not in motion, it is a rare occurrence in either case. So the disadvantage to the runner in motion by virtue of the occasional extra air ball DP can probably be ignored (it is actually worth – .0065 runs per SB attempt, or around -.26 runs per year for a 40 SB attempt player).

Let’s compute the average RE on a ground ball out against both groups of pitchers, to see the actual advantage in runs on an attempted steal of second base with less than 2 outs. We will assume that with 2 outs, there is not much of an advantage, although that is not exactly true.

Table III: RE after a GB out

Against low frequency pitchers Against high frequency pitchers
Average RE after a GB out .317 (0 and 1 out combined) .364 (0 and 1 out combined)

As you can see, there is a .048 run gain when a batter hits into a ground ball out against a Group II pitcher. This is because the runner is more often running on the pitch and ending up safe at second. From Table II above, a ground ball out happens around 13% of the time (with a runner on first only and less than 2 outs) against Group II pitchers. So the overall gain is .048 * .13 or .0062 runs with a 41% steal rate. So, per steal, that is a .0152 run gain (.0062 / .41). So being able to avoid a force out at second ball on a ground out by the batter is worth an extra .0152 runs for every stolen base attempted by a runner. If a prolific base stealer attempts 40 SB per year, that is an extra gain of .61 runs, nothing to write home about.

Finally let’s look at advancing on hits. Presumably, the runner in motion will be able to take the extra base more often that one who is not on the move. Here is the data:

Table IV: Advancing the extra base on a hit 

Against low frequency pitchers Against high frequency pitchers
Extra base on a single 41.2% 42.3%
Runner out trying to advance .8% 1.4%
Batter moves up a base 6.4% 9.9%
Extra base on a double 52.0% 51.5%
Runner out trying to advance 3.9% 2.9%
Batter moves up a base 2.8% 2.6%

Although I only looked at outfield singles, and I assume that virtually all doubles are to the OF, there is obviously no guarantee that a runner on the move will be able to take the extra base. If I had to guess, I would say that rather than a 40-50% advance rate when the runner is likely not on the move, there will be a 75-80% rate when the runner is going. Let’s see if this estimate fits the data.

From the GDP data, we estimated that the runners were moving when the ball was put into play around 8% more against Group II pitchers than versus Group I pitchers. If we expect a 35% increase in the advance rate when the runner is attempting a steal, then the overall advance rate for the Group II pitchers should be around 2.8% higher than with the Group I pitchers.  For singles, we see only a 1.1% increase and for doubles it is actually a .5% decrease (unfortunately these are very small samples – 371 and 127 opportunities, singles and doubles against Group I pitchers, respectively). If we combine them (weighted according to number of opportunities, of course), we get a .67% increase with Group II pitchers, less than expected (2.8%). Of course the 35% increase (75-80% rate of advance) in advance percentage with the runner off on the pitch was a wild guess on my part. It could be only 25% more or it could be 45% more. In addition our sample sizes of singles and doubles are so small, that the differences between the two groups is not very meaningful. So I think that our 8% or .24 runners on the move per stolen base attempt, garnered from the GB data is still a reasonable estimate.

As I did with the GDP numbers, let’s see how taking the extra base adds to the value of a SB attempt, if at all.

Table V: RE after a single or double

Against low frequency pitchers Against high frequency pitchers
Average RE after a S or D 1.186 (1 out) 1.190 (1 out)

Using the numbers in Table IV above, there is a only tiny difference in the resultant RE after a single or double with the runner on first, .004 runs. These situations occur around 20% of the time, which results in an overall advantage of .002 runs per SB attempt. Suffice it to say that advancing the extra base more often when on the move is probably not worth very much overall. Even if we assumed a 2.8% extra advancement rate, rather than the modest .67% in our small sample, that would be worth .008 runs per SB and not .002.

So, there does not seem to be much of an extra advantage from the stolen base attempt, beyond the traditional numbers gleaned from the success percentage (and catcher errors on a SB, pickoffs, pickoff errors, and balks). Staying out of the GDP and taking the extra base on a single or double are likely very small advantages, and hitting into the occasional air ball DP appears to be a tiny disadvantage. if we add up all the numbers, we get .0152 for the GB situations, .008 runs (we’ll assume the more optimistic number) for the single and double advances, and – .0065 runs for the air ball DP. That is a total gain of .017 runs per SB attempt or around an extra .7 runs per season for a high frequency base stealer.

About the only thing we have really accomplished is to estimate that a base stealer is on the move when a ball is put into play about .24 times for every time he records either a SB or a CS. In other words, around 19% of the time (.24 / 1.24) that a runner takes off, the batter puts the ball in play. Unfortunately, that extra few steps isn’t worth much to the offensive team, at least terms of what I looked at so far, staying out of the GDP and force outs, and advancing extra bases on hits.

In Part II, I’ll look at how the hitter’s results are affected by the runner attempting a steal of second (or not). Can we expect more hits when the runner is in motion because the infield is moving? Is the batter distracted by the runner going? Is the pitcher distracted with a prolific base stealer on first? Does the batter take some pitches that he might ordinarily swing at? Are some of these “runner going” situations hit and runs such that the batter is forced to swing at anything? Stay tuned for Part II…