Baseball Prospectus: Moonshot, A New View of Plate Discipline

[weams]

http://www.baseballprospectus.com/article.php?articleid=25092'>Part 3

Part 1

Part 2

In the sortables section of Baseball Prospectus, there is a report called Batter Plate Discipline. If you?re trying to get a handle on how good hitters are at reacting to balls and strikes, this section contains measurements on such things as swing and contact rates. A natural way to divide such rates is based on the strike zone: A swing at a pitch inside the zone is a different event than at one outside the zone. A whiff on a pitch middle-middle is a disparate event from a whiff on a pitch way outside, so it makes sense to tabulate them in different columns. There is a problem with this dichotomy, however: There is no strike zone.

In the words of Michael Lopez (who borrowed in turn from Bobby Ojeda), the strike zone is a unicorn. By this I mean not that the strike zone does not exist at all, but rather that it does not exist in the way that Major League Baseball defines it. The rulebook definition is a rectangular solid hanging in space, with infinitesimally thin boundaries which, once touched, trigger strike calls.

[El Gordo]

Re: the K Zone. Indeed there isn't on be but one can make a composite approximation of the various existing ones. Or compute a strike zone for each umpire and apply it accordingly.