Plate Discipline statistics tell us a wide number of things about pitchers: how effective they are at attacking the zone, how often they get hitters to chase on pitches (both inside and outside the zone), how often they throw a first-pitch strike, etc. There are a wide number of these stats:
O-Swing%: The percentage of pitches a batter swings at outside the strike zone.
Z-Swing%: The percentage of pitches a batter swings at inside the strike zone.
Swing%: The overall percentage of pitches a batter swings at.
O-Contact%: The percentage of pitches a batter makes contact with outside the strike zone when swinging the bat.
Z-Contact%: The percentage of pitches a batter makes contact with inside the strike zone when swinging the bat.
Contact%: The overall percentage of a batter makes contact with when swinging the bat.
Zone%: The overall percentage of pitches a batter sees inside the strike zone.
F-Strike% – The percentage of first pitch strikes.
SwStr%: The percentage of total pitches a batter swings and misses on.
FanGraphs carries plate discipline statistics based on both Baseball Info. Solutions (BIS) data as well as Pitch f/x data. There are some minor differences between the two systems. The Pitch f/x section presents raw Pitch f/x data broken down according to defined baselines, while the BIS section takes the Pitch F/x data and uses human scorers to modify classifications.
Please note that the following chart is meant as an estimate, and that league-average for all of these stats varies on a year-by-year basis. To see the league-average plate discipline stats for every year from 2002 to the present, check the FanGraphs leaderboards.
Things to Remember:
● These statistics are useful for evaluating hitters and pitchers, with SwStr% being especially important when looking at pitchers.
● Swinging strike percentage (SwStr% — swinging strikes per pitch) should not be confused with whiff rate (swinging strikes per swing).
Links for Further Reading: