Read Part 1.
Five things I learned about fielding in baseball from reading Bill James’s new book Win Shares:
1. Defensive efficiency, the percentage of balls put into play that is turned into outs, defined, if we ignore the small peripherals, as total outs minus strikeouts divided by the total number of balls in play, accurately measures how well a team performs defensively. You might think that pitchers would influence this statistic. They don’t.
2. You can measure range for first basemen, but this requires not just assists, but unassisted putouts, which are usually made when he runs to the bag himself instead of flipping to the pitcher. You can approximate this second component by subtracting all of the other infielders’ assists from the first baseman’s total putouts.
3. Catcher fielding percentages are a lot more meaningful when you remove strikeouts, which absurdly bloat the catcher’s total chances and never should have been there in the first place.
4. Because fielding, unlike pitching or hitting, is a cooperative effort, it must be evaluated top down — first on the team level, and only then by assigning contributions to individuals. (James also argues that this is the best way to evaluate everything, but I’m sure he would agree that you can get a lot further with pitching and hitting by working from the bottom up.)
5. Fielding statistics, like many things, make a lot more sense in context. If Bill Mazeroski, who has the best all-time double play statistics of any second baseman, turned a lot of double plays, we need to figure out how many he had a chance to turn, and we can. If Richie Ashburn, who has the best all-time fielding statistics of any outfielder, caught a lot of fly balls, we need to figure out how many he had a chance to catch, and we can again. In fact Ashburn achieved them partly because he was in fact a superb defensive player, but mostly because the Phillies’ pitching staff in the 1950s gave up more fly balls than any other pitching staff ever, by far. For the same reason that team’s shortstop, Granny Hamner, has lousy fielding statistics, even though his defensive reputation was excellent. Mazeroski, on the other hand, had more or less the normal number of opportunities to turn double plays. He really was that good.
Maybe these things are obvious. But I didn’t think of them, and neither did you.