Baseball Therapy: Is There a Pinch-Fielding Penalty?

I have a fascination with super-utility players, the guys who can play anywhere on the diamond. Players like Tony Phillips, Ben Zobrist, or even Denny Hocking. They're so handy to have around because a manager can fill out a lineup with a little more flexibility and know that he has someone to fill whatever hole is left. He's a wild card that gives a general manager more choices when putting together a roster. He's the type of player who adds a little extra value that the box score— and WARP—don't really capture.

In 2000, BP alumnus (and full disclosure, a man with whom I have worked) Keith Woolner asked a series of questions that he titled "Baseball's Hilbert Problems." At the time, it was a compendium of questions that he felt would drive the field in the century to come. At no. 6 on his list, he asked the question of how we might actually value this sort of positional flexibility. Reading through the rest of Woolner's questions, we've actually made quite a bit of progress in the first eighth of this century on several of them. But not this one.

I'd propose that one reason that sabermetrics hasn't progressed in this particular area is that while we've gotten good at describing various pieces of a player's performance that provide value, we've only ever looked at the player himself. When a player hits a home run, we credit his account. But what do we do when some other factor about the player allows his team to do something positive more often? Maybe a player can play both first base and left field decently, and his team happens to have a right-handed-hitting first baseman who mashes lefties and a lefty left fielder who is unkind to northpaws. The team can construct a nice platoon, with much better results than playing either player full time, but only because of the versatility of the third wheel.

Getting the platoon advantage more often is a big deal. There's a reason that teams carry LOOGYs and go to all the trouble of making five pitching changes in an inning. The platoon advantage is worth about 20 points of OBP. Because our super-utility guy is so super, his team can take advantage of that more often, and it will perform better as a result. It's not a stretch to say that some portion of the credit for the team's increased production should go to the versatile guy for enabling that to take place.

I'd like to begin an arc of articles here at BP on the matter of what I'm calling "latent talent." It's talent that derives not from what a player does, but because of the effect that what he does has on the other players on his team. Can a team extract extra value from finding parts that fit nicely together and make something that is more than the sum of its parts? Is there an effect of Ben Zobrist for just being Ben Zobrist? I'd suggest that the answer is yes, and maybe the rewards can be even bigger than you might think.

The platoon-enabling issue is an obvious case. But I that think before we encourage each team to find its own Ben Zobrist, there's an issue to tackle. While a team could use the platoon to its advantage, even mid-game, it would require that our Zobrist actually ping back and forth between positions on a regular basis. We know that there is a "penalty" that hitters pay when they pinch hit. This will sap some of the advantage of the platoon. But we need to ask a related question. After the pinch hitting appearance, we will have one player just entering the field, while another has to switch between positions. Must we give back some of the advantage that we think we're getting to a "pinch fielding" penalty? Do substitute fielders perform worse than starters?

Warning! Gory Mathematical Details Ahead!
I looked at two types of events: infielders fielding ground balls and outfielders catching fly balls. I used the 1993-1999 Retrosheet database, since it has data on hit locations. For infielders, I looked at all balls hit in their immediate zone (i.e., the “6” zone for the shortstop) as well as to the zone immediately to their right and left. I calculated the percentage of balls that the infielder reached and turned into outs over the course of the season. For the outfielders, I used fly balls to the outfielder's primary zone, as well as to the zones immediately behind, in front of, to the left, and to the right of that zone. I turned that percentage into an odds ratio and took the natural log.

I then created a binary logit regression and put in the control variable of the fielder's general prowess at that position. I then coded for whether the fielder was the original starter at that position, or a substitute (who started the game on the bench), or a starter at another position who had shifted to this new spot. I ran a series of tests for each position and various comparisons. (Did it matter whether the fielder was a starter at this position vs. a starter who was from another position? Was there a difference between a transplanted fielder and a direct substitute?)

For infielders, there was a general pattern that for third basemen, there was some benefit to being the starter (rather than a substitute from the bench), in the sense that while numbers for first basemen, second basemen, and shortstops generally did not go near significance, the p-values for third basemen were around .20. For outfielders, there were no significant effects observed.

What it all means
For the most part, substitute fielders do not suffer the same problems in fielding their positions that a substitute batter does in hitting the ball. This should be interpreted as, "Players field their position with the usual efficiency that we see from them, no matter whether they started at the position or moved there." Our versatile guy might be decent at one position, and bad at another, and that has to be taken into account, but he won't suffer any ill effects of switching positions mid-game.

I should also point out that this is not license for managers to simply shift any player anywhere on the field. The players who made these moves did so because their teams felt that they were capable of doing so (or the team was desperate). But then again, those are the same versatile utility guys of whom we are already speaking. It means that managers can pursue these split platoons with reckless abandon because of this Zobrist Effect.

And now that we have an idea of what the Zobrist Effect can do for a team, we can get about the business of conceptualizing how much it is worth.