The Stats We Use: Baserunning

Believe it or not, baserunning is a relatively simple aspect of the game to quantify. If you think for a moment about the possibilities in baserunning, there aren’t really that many of them. There are several of course, but it’s not as many as you may think. For example, a runner on 1st when a single is hit can move to 2nd or 3rd. On rare occasions he may move all around the bases. A runner could be on 2nd when a single is hit and he can go to 3rd or home. The baserunners could also be thrown out. There could be a baserunner at 1st when a double or triple is hit. There are stolen bases, caught stealings, pickoffs, and a number of others.

That probably sounds like a lot and it’s more than I made it sound like at first. However, we have a run expectancy table to help us quantify the value of these baserunning events. Before we go further, the run expectancy table is the heart and soul of advanced baseball metrics. The run expectancy table tells us exactly how many runs have scored in the various situations. The run expectancy table isn’t anything new. It’s not a newfangled set of statistics or anything like that at all. George Lindsey was writing about the run expectancy tables in the early 1960s. It’s been around for a long time.

Here’s the simplest of run expectancy tables using 1999 to 2002 data. Between those years at the start of an inning, teams averaged .555 runs that inning. If the first batter made an out, it decreased their RE to .297. That out cost the batting team the difference between those two in runs. With a runner on 1st and no outs, teams scored .953 runs. Imagine a single is hit. 1st and 2nd is 1.573 runs. Let’s say the baserunner goes 1st to 3rd on that single. The RE with runners on the corner and no outs is 1.904. The baserunner added the differene (1.904-1.573) in runs by going from 1st to 3rd rather than 1st to 2nd. That’s how many runs in that situation that baserunner provided his team. Imagine that same runner was thrown out at 3rd instead. The RE with 1st and 2nd is 1.573 runs again, but now there’s one out and only a runner on 1st base. The RE dropped to .573 runs. The baserunner cost his team exactly 1 run by trying to add the extra base. As you can see, the out is far more valuable than the extra base. It’s not even close. The extra base added .331 runs while the out was worth -1 run. The out in baseball is especially valuable once a batter reaches base.

It’s why a lot of people aren’t huge fans of the stolen base. Stealing 2nd with noboby out adds .236 runs while getting thrown out at 2nd costs you .68 runs. It’s why people say you have to be successful close to 70% of the time to make it worthwhile.

That table is the average. There are actually different run values depending on the state of the game. A successful stolen base in the 9th inning of a tie game is worth more. The same is true for other baserunning events. The close and later the game is, the more valuable those extra bases are. However, the outs are also more costly.

Anyway, you simply apply the RE table (in-season of course) to the various possibilities. Baseball Prospectus provides Equivalent Baserunning Runs (EqBRR). It includes the number of runs a player was worth on balls hit on the ground or ones hit in the air. It includes the value of runs after an out was made, stolen bases and of course the outs made in the process. There are actually five different categories that are added to get EqBRR: Ground Advancement, Air Advancement, Stolen Bases, Hit Advancement and Out Advancement. The first thing you do is comb through the play by play data and find the number of opportunities in each area. Then you calculate the average for all players and compare each to the average player in terms of runs added or subtracted.

If the average player went first to third on a hit X number of times while another player did it X+3 then he’s above average in that category. The same is true if a player advances on an out as well as the other categories more than the average player does so. Let’s say a player advanced from 1st to 3rd three more times than average. The value of those three additional bases is the difference between men on 1st and 2nd and men on 1st and 3rd times the number of times the player advanced above or below average. Making outs on the bases as well as stolen bases obviously affect baserunning. 

There’s a little more to EQBRR than I’ve made it sound like. If you have a subscription to Baseball Prospectus you can find many of the links discussing each category in this article

Few players each season are worth more than 6 runs on the bases. Last year there were only 10 and the year before just 5. Only 7 players have been worth -6 or fewer runs on the bases over the last two seasons. Most players are going to end up in the -2 to +2 range. Baserunning, at the team level especially, can be quite valuable. For a player like Carl Crawford, it’s certainly part of his value going forward (at least until he ages and the speed declines). It’s an important part of the offense that has to be added in when we’re looking for that one tell-all metric (WAR). 

Berselius and I have written about the Cubs awful baserunning in the past. He did so on this blog. The Cubs, as a team, are nearly -50 EqBRR since 2006. That’s an average of -10 runs per season. A win is 10 runs, or 10.5 to be precise. The Cubs have cost themselves 5 wins over the last 5 seasons. Not that big of a deal when you think about it, but the Cubs are also very poor defensively. In two ways teams can improve noticeably, the Cubs are very bad at those areas. The Cubs are left looking for positive contributions from their offense and pitching. It hasn’t gone so well on the offensive side of things since the end of World Ward II. Since the end of the war, the Cubs have had exactly one season in which they have been better than league average on offense. That was 2008 and they were only a few percentage points better than the league average.

Mike Quade made an intelligent decision at the end of spring training when he said the team would not be running as much. Earlier he had said they were going to be aggressive, but I’m guessing 7 stolen bases in all of spring training compared to 8 times being caught helped change mind. The best thing the Cubs can do to improve on the bases is to stop trying to steal them. They’re not good at it. No reason to insist on doing something you aren’t good at. I’m not good at surgery and I’m not insisting on performing one. Know your limitations. I’ve ripped on Quade before, but to me, that’s worth a lot.


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