Twins 8, Brewers 6 and Stealing Bases

The Minnesota Twins won last night, swiping (and sweeping) the season series from the Milwaukee Brewers. The victory raised their record to 23-28 which translates to a 73 win pace over the course of a 162-game season.

But I want to talk about a different type of swiping that happened, or more accurately, did not happen. In the bottom of the sixth inning, Aaron Hicks was caught trying to steal second base. What struck me as strange at the time was that there were runners on the corners and one out. It seemed like a stupid decision to attempt that at the time, as it can short-circuit a good scoring opportunity. However, one always looks stupid when one is caught. So I wondered, was it as risky as it seemed?

It turns out – I studied this exact situation last year on 5/11, only it was Denard Span that was thrown out. Here’s how that went:

Generally, one studies something like this using Palmer & Thorn's Run Expectancy Matrix. It's a neat grid that shows, given a certain number of outs and people on base, the average number of runs that should score that inning, based on 75 years of major league games. It was published in The Hidden Game of Baseball by Pete Palmer and John Thorn. You can find it here.

Here's the numbers we care about:

1. 1.088 - That's how many runs a team on average would score with runners on 1st and 3rd and one out.

2. 1.371 - If Span would've stolen the base, that's how many runs the average team would've scored.

3. 0.382 - If he was caught, that's how many runs the average team would score.

So Span risked a gain of .283 runs if he stole that base, but a loss of .706 if he was caught. Converting those to percentages, if he steals that base 71% of the time, the team breaks even. That's not especially different than the 2/3 view that is the case for most base stealers. This wasn't especially risky.

Tonight, though, I want to take it a step further. How does it compare to other situations in which one might try to steal a base?

There are 12 situations where a runner might try to steal a base without coordination with the other runner. Here they are:

Runner on 1st, 0 outs

Runner on 1st, one out

Runner on 1st, 2 outs

Runner on 2nd, 0 outs

Runner on 2nd, 1 out

Runner on 2nd, 2 outs

Runners on corners, 0 out

Runners on the corners, 1 out

Runners on corners, 2 outs

Runners on 1st and 2nd, trying to steal 3rd, 0 outs

Runners on 1st and 2nd, trying to steal 3rd, 1 out

Runners on 1st and 2nd, trying to steal 3rd, 2 outs

And here they are again, ranked by just how risky they are. The percentage indicates how often one needs to succeed for it to be a good decision.

92.51% - Runners on 1st and 2nd, trying to steal 3rd, 2 outs

91.10% - Runner on 2nd, 2 outs

79.67% - Runner on 2nd, 0 outs

77.69% - Runners on 1st and 2nd, trying to steal 3rd, 0 outs

77.25% - Runners on 1st and 2nd, trying to steal 3rd, 1 out

75.31% - Runner on 2nd, 1 out

74.74% - Runners on corners, 2 outs

71.39% - Runners on the corners, 1 out

70.73% - Runners on corners, 0 out

65.20% - Runner on 1st, 0 outs

63.41% - Runner on 1st, one out

60.06% - Runner on 1st, 2 outs

So it wasn’t patently stupid, like trying to steal 3^rd when you’re already in scoring position. But it was the 2^nd riskiest situation in which to try to steal 2^nd base. The only thing that would have been worse was if it could have ended the inning.