Why Do Teams Even Attempt to Steal Bases?
A general belief among many people in baseball is that if a
player is stealing at less than a 75% success rate, they are better off not
attempting to steal at all. With just a 72.48% league average stolen base rate and
only a limited amount of true stolen base threats in the MLB, why do teams even
attempt to steal bases? The obvious answer to this question is to give the team
a better chance of scoring a run or multiple runs that inning.
The downside to attempting to steal bases, however, is that
getting caught stealing can be detrimental to a team’s chances of scoring a run
or multiple runs, as we can see with this run-expectation table provided by Baseball Prospectus:
| # | LVL | YEAR | Runners | 0 OUTS | 1 OUT | 2 OUTS |
| 1. | MLB | 2014 | 000 | 0.4552 | 0.2394 | 0.0862 |
| 2. | MLB | 2014 | 003 | 1.2866 | 0.8873 | 0.3312 |
| 3. | MLB | 2014 | 020 | 1.0393 | 0.6235 | 0.2901 |
| 4. | MLB | 2014 | 023 | 1.8707 | 1.2714 | 0.5351 |
| 5. | MLB | 2014 | 100 | 0.8182 | 0.4782 | 0.1946 |
| 6. | MLB | 2014 | 103 | 1.6496 | 1.1261 | 0.4396 |
| 7. | MLB | 2014 | 120 | 1.4023 | 0.8623 | 0.3985 |
| 8. | MLB | 2014 | 123 | 2.2337 | 1.5102 | 0.6435 |
This chart clearly shows the significant downside to attempting to steal bases and getting thrown out at a high rate. For example: Billy Hamilton draws
a walk and, with Astros’ starting pitcher Scott Feldman (-5 wSB) on the mound, Hamilton decides that
he is going to attempt to steal second base on the first pitch. Feldman throws
a fastball up in the zone, and somehow, Jason Castro manages to throw Hamilton
out at second base. Over the course of just two pitches (the one Hamilton drew
the walk on and the one Hamilton attempted to steal on), the chances of the
Reds scoring a run changed dramatically. When Hamilton drew the walk at the
beginning of the inning, the Reds had a runner on first and no outs, which was
worth a total of .8182 runs. After getting thrown out on the steal attempt, the
Reds had no runners on base and one out, which is worth just .2394 runs. On the
other hand, if Hamilton was successful stealing 2nd base, the Reds
would have a runner on second base and no outs, which is worth 1.0393 runs
(just a .2211 runs increase). Overall, attempting to steal second base in this
situation carries a lot risk and not enough upside for it to be justifiable. Even one of the best base stealers in the MLB, Billy Hamilton, was successful
just 70.9% of the time last season. And while he managed to steal the second most bases in the MLB last season, Hamilton posted a less impressive 2.0 wSB considering that he swiped a total 56 bags.
All in all, the problem with attempting to steal bases is
not that teams do it. Instead, it is the fact that teams attempt to steal bases
too often and at the wrong time. The stolen base should be primarily used late
in 1-run games with base runners that are going to be successful a high
percentage of the time. Some teams sacrifice the opportunity to maximize their run potential by playing like it is the last inning of tie ballgame every inning. The Texas Rangers stole 105 bases last season; a number
that was good for the 8th most in the MLB. The problem, however, is
that the Rangers were caught stealing 69 times, and they had the third worst
stolen base percentage (64.02%) in the league. The Rangers tried to steal early
and often, but they finished the season with the second worst wSB (-7.1), and in
reality, they would have been better off not attempting one stolen base the
whole season. This is a perfect example of a team that could have scored a lot more runs if they were not so dedicated to baseball's beloved stolen base.
