Teams employ the shift against Ryan Howard on the bet that he will pull the ball. As David Ortiz showed back on April 23, 2006, bunting against the shift can be done for fun and profit. Well, perhaps not profit. The conservative line is that sluggers like Ortiz and Howard “aren’t paid to bunt.”
Going off the assumption that sluggers are paid to win games, we investigated whether WPA (win probability added) suggests that Ryan Howard should learn to bunt against the shift. Conventional wisdom, and Charlie Manuel, would say that Howard should not bunt because of his potential to hit a home run. Opponents’ use of the shift suggests that they think similarly.
To simplify things, we looked at Ryan Howard’s plate appearances with nobody on base (the time most likely to see the shift).
We took Howard’s career (through 8/4/10), bases-empty, average WPA for his home runs, singles, doubles, triples, walks and outs. Then we calculated the probability that he does each of these things, based on his career rates of each result with nobody on base. We multiplied the WPA for each event by the likelihood of each event, and added them together (typical expected value formula).
We calculated the expected WPA of a bunt attempt based on the expected WPA of a single, a walk, and an out (the three outcomes of his attempt at bunting) and the probabilities of each event based on Howard’s career rates.
The result was the graph below:
WPA is more of a descriptive tool than a predictive one, but frankly, we were surprised by what we found. The green line is the break even point. In any bases-empty situation (the red line), Howard improves his WPA if he is successful in only 40% of his bunt attempts. With no outs and the bases empty, the WPA of a 70% success-rate bunt is an astounding 20x the WPA of swinging away. Considering the vast real estate available to Howard on the third base side of the diamond, and his well-known work ethic, it is not unreasonable to think that Howard could become a 70% bunter.
This, of course, will never happen for two reasons. The first is that Charlie Manuel would never allow Howard to become a notorious bunter on his watch. The second is that if Howard became one, teams would employ the shift less. In this second scenario, however, Howard makes the defense pick their poison. If they shift, he threatens bunt. If they don’t shift, his chances of a single or double increase. Howard is a team player, and his big, home-run-based contract is signed, sealed, and delivered. The incentives for Howard to start bunting are there, and you know Citizens Bank Park (and Jimmy Rollins) would get a kick out of it.
Authors: this post and the research therein was written and conducted by Mike Lipsitz and Nicholas Mirra. Statistics were obtained from fangraphs.com and baseball-reference.com.