In The Only Rule Is It Has to Work, the excellent new book by Ben Lindbergh and Sam Miller, the authors served as the baseball operations department for the Sonoma Stompers, an independent league team in the Pacific Association of Professional Baseball Clubs. The analytically inclined writers-turned-executives were given freedom to make roster, lineup and strategical decisions based on data, and among the most radical ideas explored in the book is the implementation of a five-man infield against an opposing player named Scott David.

The Stompers deploy a five-man infield against Scott David of the Pittsburg Diamonds, with Mike Jackson Jr. on the mound. (Source)

David is one of the best hitters in the league, one with seemingly no exploitable flaws in his approach, and the authors were struggling to come up with anything substantial to provide their pitchers in a scouting report. That is, until an off-hand remark was made about the possibility of enacting a five-man infield, and the realization that David was, in fact, the ideal candidate for the radical defensive alignment, for four key reasons:

1. He hits a bunch of ground balls
2. He sprays those ground balls all over the infield
3. He is an effective ground ball hitter
4. He has very predictable fly ball tendencies

As soon as I finished the chapter, I knew I needed to find Major League Baseball’s Scott David. Into the numbers I dove.

Using the FanGraphs leaderboards and BaseballSavant, I was able to put a number on each of the four tendencies above. Step one, ground ball rate, is simple enough to find. For step two, I calculated the difference between pull ground ball rate, and opposite-field ground ball rate to serve as a proxy for how often a player sprays his ground balls. For step three, I simply used ground ball OPS — no point in bringing in an outfielder if the player’s ground balls aren’t doing any damage. And for step four, I found the absolute value of a player’s pulled fly ball rate as a way to highlight predictable fly ball tendencies. Then I summed the z-scores of each of the four numbers to come up with a “Five-Man Infield Score.”

In the top five, we find guys like Eric Hosmer and Nori Aoki, but doing this to a lefty, as Lindbergh and Miller did, is admittedly more dangerous due to the exposure of the right field corner for an easy triple. Right-hander David Freese pulls too many of his ground balls; a normal infield shift will do the trick for him. Jean Segura is a decent candidate, though his ground ball rate and spray tendencies are not nearly as extreme as the number one name that pops up on our spreadsheet, far and away the most ideal candidate in Major League Baseball for the five-man infield: Howie Kendrick.

Look no further than his spray chart for convincing. The yellow dots are rough estimates of the optimal positioning against Kendrick in the proposed five-man infield:

Kendrick’s hit a ground ball on 65% of his balls in play, one of the highest rates in baseball. He hits them all over the infield, so shifting him with four infielders is impossible, and while Kendrick has been a pretty poor hitter this year, his OPS on ground balls is actually above-average, so there’s still hits to be taken away here. And as we can plainly see in his spray chart, there simply hasn’t been a need for a left fielder against Kendrick, so bring him in to play behind the second base bag, shift the the center fielder over slightly, and, voila! We’ve got a five-man infield, perfectly designed for Howie Kendrick, the only obvious candidate for a five-man infield in today’s MLB.

Now who’s going to be the first team to do it?