Last month we learned that Major League Baseball will be implementing a new extra innings rule aimed at reducing the length of games: each extra inning will start with the batting team placing a runner on second base. The runner, which will be the player who made the final out of the previous inning, is considered to have reached base via error. If he scores, his run will be counted as an unearned run.
When the new extra innings rule was first announced I and many others suspected that it would lead to a sacrifice-bunt-a-rama. That, teams would always try to move the runner over with a bunt, thinking that having a runner on third base with one out would be better than most other scenarios because a run could score on a wild pitch or a sac fly in addition to a base hit. In my own case this belief was bolstered by anecdotal evidence: I’ve been to three minor league extra inning games and in all three of them both the visiting and home team began their respective halves of the tenth with a sac bunt attempt.
As is almost always the case, however, it’s a good idea to set aside conventional wisdom and your own lyin’ eyes when assessing something where there is broader data available. We learn that today via an article from MLB.com’s Mike Petriello, who crunched numbers in an effort to see whether that 10th inning sac bunt is a good idea and whether an increase in bunts would accompany the new extra innings rule.
You should read the whole article because it breaks down the strategy from multiple perspectives — and includes an analysis of not just whether the team on offense should bunt but whether the team on defense should issue an intentional walk — but the upshot is that, in thousands of minor league extra innings games . . .
- The visiting team bunted to start their inning only 22 percent of the time under the new extra innings rule;
- The home team, when tied, bunted to start the inning only 31 percent of the time under the new extra innings rule; and
- The home team, when behind, bunted to start the inning just 13 percent of the time under the new extra innings rule.
Some of this is immediately intuitive. If you’re the home team, in the bottom of the 10th, down by two runs, you’re going to need at least two runs to avoid a loss, and in that case you do NOT want to give up the out a bunt will cause. Some of this makes sense the moment you set aside the conventional wisdom, look at the numbers and realize what the run expectancy is for a runner on second with no outs vs. a runner on third with one. There are, obviously, adjustments to be made based on who the specific hitter is, who the runner is, and all of that, so the base run expectancy doesn’t rule all, but on the whole, bunts are far less favored than might first be believed.
Which, given that we’re in an age where every front office staff knows this data just as well as the stat folks at MLB.com do, and that they’re going to instruct their managers and coaches about all of this as well, means that we’re not gonna see a huge number of bunts as a result of the new extra innings rule. Or at least we shouldn’t.