Orioles Rays BaseballAlan Schwarz of the New York Times wrote a great article about the use of simulations in baseball. in doing so, Schwarz looked at the impact of specific aspects of the game. One of those was the stolen base. Specifically, Schwarz showed that if a team such as the Tampa Bay Rays were to steal fewer bases, they would actually score more runs.

The stolen base. Advancing from first to second puts the runner in scoring position, but he — and the rest of your hitters — will have a hard time scoring if he gets thrown out. Mr. Kraemer looked at a recent team that ran wild (the 2008 Tampa Bay Rays) and one that barely stole at all (the 2005 Oakland A’s) and switched their mind-sets to see what happened. The A’s scored 20 runs fewer, which probably says more about their players’ inability to run in the first place. But when the speedy Rays stole sparingly, they increased their scoring by 47 runs per season — suggesting that perhaps the Rays were running too often in real life.

This caught the attention of Rob Neyer at ESPN.

On the other hand, the note about the Rays’ steals is truly surprising. The generally accepted break-even point for steals is something between 70 and 75 percent (depending on the scoring environment). Well, last season the Rays stole 142 bases and were caught 50 times for a 74 percent success rate, comfortably within that break-even range. I don’t know how to square 74 percent with those theoretical 47 runs … but if I were running the Rays, I sure would want to know.

First of all, we love baseball simulations. But we are the first to tell you that there are inherent limitations. Simulations, such as the highly respected “Diamond Mind” look at trends and averages and uses those to project what will happen over the course of a season. What they cannot do is project what will happen in very specific situations.

In the case of stolen bases, simulations look at a team like the Rays and see how often they steal and how often they are successful. What the simulations don’t see is when the Rays steal and what impact those steals have on other aspects of the game.

More specifically, the simulation will see that the Rays attempt 192 steals in a season or about once every 30 plate appearances. So when the simulator does its thing, it will have the Rays attempt a steal about once every 30 plate appearances without any further rhyme or reason.But even for a team like the Rays, there are times in the game when they are more likely to steal and times when they won’t because stealing a base would hurt the ballclub.

Furthermore, Diamond Mind only considers a stolen base as moving forward a base or being called out. But stealing a base is so much more than this simplistic view. A simulator does not consider the psychological impact on the pitcher and how he can be distracted. It does not consider whether the pitcher is throwing from the stretch or going to the plate with a quick pitch because somebody like Carl Crawford is on first base. It does not consider that a pitcher may throw more fastballs with BJ Upton on first base, and how that benefits the batter.

This is fine over the course of a full season because these type of idiosyncrasies will tend to even out. In other words, the negative impact of facing a fast team like the Rays is balanced out by all the positive impacts of facing a team that does not steal bases at all, like the A’s.

So what does this tell us? It suggests to us that simulations severely underestimate the impact of base stealers on a baseball game and on the success of a team over the course of 162 games. This could be one reason that the Rays beat even the most optimistic projections last season by 10 games, despite not having any players play above their expectations.

We love projections and we love statistics (we used to teach a statistics course) but with great power comes great responsibility. One has to be careful how they are used, and one has to understand the limitations.

Answering Baseball’s What-Ifs [New York Times]
Computer simulations sometimes offer surprises [ESPN]



  1. BillyCan says:

    Mark Twain once said "there are lies, damn lies, and statistics". Not taking into account the situation that a steal attempt takes place, and the threat of the baserunner going has on a pitcher and pitch selection officially puts this simulation in the damn lies category.

  2. Dirtbag Fan says:

    Does the program consider pick-offs or just caught stealing? Does it even matter?

    I say it because more than once last year someone (ahem...Bossman) was caught sleeping while leading-off, he wasn't actually attempting a steal, but I'm sure it went down as a "caught stealing" right? So that skews the stats... I'm not a huge stats guy, so I'm a little over my head here, just curious.

    And technically, in my mind, baserunning errors shouldn't be considered caught stealing either... there should be an offensive error catagory.

  3. Possum Avenger says:

    Agreed. The guy that ran this simulation is using the same logic as people who say "never bunt." It doesn't take into account the different situations -- score, how dominating the pitcher is, where the infielder is playing, etc. The specific variables in a game cannot be factored in to simulations which is one of their ultimate limitations, although they remain useful. When I, and other, get dismayed with simulations is when people make proclamations like "don't bunt" or don't steal based on their results. You need context.

    • Robert Rittner says:

      I have never read anyone who said "never bunt". I have read many who claim that the effectiveness of the sacrifice bunt is wildly overrated, and I think they are right. In fact, I thought that idea was right 50 years ago before the data demonstrated the foolishness of sacrificing automatically.

      The current thinking on the matter simply points out that the sacrifice bunt increases the chances of scoring one run but decreases the chances of a big inning. Therefore, before deciding to use it, the manager has to consider the situation his team is in and the specifics of the circumstances (who is on base, who is up next, who is pitching, the inning, the score et al.) Nobody is saying never bunt; they are saying that sacrificing for one run in the first inning with your number 2 batter is probably counter-productive. Yet many managers have continued to use that tactic automatically regardless of the actual circumstances as if we were still playing in the deadball era when 1 run was far more valuable than it is today.

  4. Joe D. says:

    I love simulations, video games, and especially games that have things like general manager modes, ect...

    There is nothing though, that can take into account someone like Edwin Jackson. I remember a game last season, I forget who it was against or anything like that, but some one fouled of a couple of good pitches, and he just lost it. You could see, his facial expressions change, he started over thrown, his mechanics went down the drain, he would start playing with and adjusting his jersey, tugging at his cap, before you know it he's given up 4 runs with 2 outs.

    I don't think that there is any good way to quantify in a simulation how pitchers might be mentally affected from working out of the stretch, having to throw over to first, hurrying things, staying away from slower pitches, or breaking pitches that can easily get away from a catcher. But human's, managers and player do know that, and can force the issue. I agree that this a flailing point in computer simulations.

  5. Mike says:

    48 graphs from DRB explaining the ZOMG!!! awesomeness of stolen bases in 4...3...2...1...go

  6. Scot says:

    Prof - I partially agree with you and partially disagree. Based upon my 10+ years of using Diamond Mind software, I can say that the study is questionable - not because the software does not include the "intangibles" of what a stolen base can do, but rather how the stolen base is programmed into the software. In my experience, the software chooses poor or simply pointless times to steal. In addition, while it tries to limit the steals to those who steal the most, far too often Navaro will be asked to steal third.

    You make this point early on. This study may not be testing the value of the stolen base, but rather how well this program simulates the use of the stolen base.

    I'm not sure if I agree with your latter point with regard to the "the psychological impact on the pitcher and how he can be distracted". Baseball Prospectus, after spending lots of time trying to extract anything out of the data with regards to the psychology of a pitcher facing a batter with a speedy baserunner on base, affirmed what you claim - speedy baserunners do affect the pitcher's performance. But the impact is so minimal, it really isn't worth discussing.

    At this point, I see claims about a pitcher's psychology are comparable to the "clutch hitter" or how a good hitter can "protect" a fellow hitter. Trying to distinguish these affects from the null hypothesis is, or nearly is, impossible.

    As for Jackson - he way outpitched everyone yesterday - the Tiger bullpen couldn't keep the hapless Jays from scoring. Joyce isn't quite ready for the big leagues yet.


Leave a Comment