Sacrifice bunting with your best hitter
May 16th, 2012 by PipIf you check the record book, you’ll find that the Cubs once sacrifice bunted against the Cardinals in a game four times, and not one was the pitcher. And you don’t have to go back to the 1920s to find it — it happened Monday night.
One of these bunt-happy Cub attempts in particular raised the eyebrow of at least one fan, reader “Brandon.” In the eighth inning of a tie game, the Cubs’ third-place — and presumably best — hitter, Starlin Castro, tried to lay one down with runners on first and second and none out. In a play that Keith Hernandez would’ve been proud of, Lance Berkman pounced on the ball and began a beautiful 3-5-4 DP.
Though we are often skeptical of the utility of sacrifice bunting, the issue for both Brandon and us was as much whether a team should ever have its best hitter sacrificing as it is whether to bunt, period. We’re talking about a career .344 OBP hitter in Castro.
We ran the scenarios using the 2nd Guesser app, and the results surprised us. Based on a 73% chance of successfully bunting and Castro’s career OBP, sac bunting in that game situation was actually a good idea (win expectancy declines more if you hit away than if you bunt). Actually, bunting would’ve been a smart call for just about anyone on either team: At that bunting success rate, the break-even OBP point is roughly .440 (Berkman boasts the highest career OBP of anyone in Monday’s game at .409).
The catch, however, is in that bunting success rate, which the Guesser assumes to be 73% (which was the league average last year). It just so happens that, despite his considerable other baseball talents, Starlin Castro isn’t very adept at sacrifice bunting, successful at a below-average 57% rate. Plugging in that number yields a very different outcome: Instead of bunting being the wise move, it now becomes a wash (Net WE for hitting away is around 14, as is bunting). For the record, Big Puma has a 100% sac-bunt success rate — on one attempt.
Of course, the rest of the context is necessary to the overall calculation, too. Following Castro was LaHair, who, as Brandon notes, would’ve almost surely been walked intentionally. That would’ve brought up Alfonso Soriano, not a bad bet for a strikeout or inning-ending GIDP. It’s all academic at this point, of course.
Beyond strategy, we wondered just how often a team’s best hitter — or at least the hitter that the manager believes to be its best by batting him third in the lineup — sacrifices. Berkman, for example, has had a plurality of plate appearances batting third and has attempted it but once in 7462 PAs. So far this season, a #3 hitter has successfully sacrificed only twice (Josh Reddick and Jimmy Rollins), and it happened only 19 times last year. Most of the list includes players who are established bunters (Placido Polanco, 75%, Freddy Sanchez, 76%) or poor-OBP men (Jason Bourgeois, Xavier Paul) or both (Omar Infante, 68%/.319). One might note that in 16 of the 19 successful sacrifices, the play was a negative WPA.
And in case you’re wondering, that legendary third-place hitter Hernandez had a 67% success rate* sacrifice bunting to go with his .384 career OBP.
*Full disclosure: MLB average during Mex’s career was 78%.


