I have had a tough time finding this information online in one place, so I thought I would amalgamate it here. Many of the descriptions come from a Fast Balls article from 2007, but there have been many variables added since then. In most cases it was obvious so I’ve spelled out a description.
| Variable Name | Description |
|---|---|
index |
A unique identification number per pitch within a game. The numbers increment by one for each pitch but are not consecutive between at bats. |
pitch_type* |
AB: Automatic Ball |
AS: Automatic Strike |
|
CH: Change-up |
|
CU: Curveball |
|
EP: Eephus |
|
FC: Cutter |
|
FF: Four-Seam Fastball |
|
FO: Forkball |
|
FS: Splitter |
|
FT: Two-Seam Fastball (synonymous with SI) |
|
GY: Gyroball |
|
IN: Intentional Ball |
|
KC: Knuckle Curve |
|
KN: Knuckleball |
|
NP: No Pitch |
|
PO: Pitchout |
|
SC: Screwball |
|
SI: Sinker (synonymous with FT) |
|
SL: Slider |
|
UN: Unknown |
|
game_date |
Date the game was played (yyyy-mm-dd) |
release_speed |
The pitch speed, in miles per hour and in three dimensions, measured at the initial point, y0. Of the two speeds, this one is closer to the speed measured by a radar gun and what we are familiar with for a pitcher’s “velocity” . |
release_pos_x |
The left/right distance, in feet, of the pitch, measured at the initial point. |
release_pos_z |
The height, in feet, of the pitch, measured at the initial point. |
player_name |
|
batter |
|
pitcher |
|
events |
|
description |
|
spin_dir |
|
spin_rate_deprecated |
|
break_angle_deprecated |
|
break_length_deprecated |
|
zone |
|
des |
A brief text description of the result of the pitch: |
Ball |
|
Ball In Dirt |
|
Called Strike |
|
Foul |
|
Foul (Runner Going) |
|
Foul Tip |
|
Hit by Pitch |
|
In play, no out |
|
In play, out(s) |
|
In play, run(s) |
|
Intent Ball |
|
Pitchout |
|
Swinging Strike |
|
Swinging Strike (Blocked) |
|
game_type |
|
stand |
|
p_throws |
|
home_team |
|
away_team |
|
type |
A one-letter abbreviation for the result of the pitch: |
B: ball |
|
S: strike (including fouls) |
|
X: in play |
|
hit_location |
|
bb_type |
|
balls |
|
strikes |
|
game_year |
|
pfx_x |
The horizontal movement, in inches, of the pitch between the release point and home plate, as compared to a theoretical pitch thrown at the same speed with no spin-induced movement. This parameter is measured at y=40 feet regardless of the y0 value. |
pfx_z |
The vertical movement, in inches, of the pitch between the release point and home plate, as compared to a theoretical pitch thrown at the same speed with no spin-induced movement. This parameter is measured at y=40 feet regardless of the y0 value. |
plate_x |
The left/right distance, in feet, of the pitch from the middle of the plate as it crossed home plate. The PITCHf/x coordinate system is oriented to the catcher’s/umpire’s perspective, with distances to the right being positive and to the left being negative. |
plate_z |
The height of the pitch in feet as it crossed the front of home plate.on_3b |
on_2b |
|
on_1b |
|
outs_when_up |
|
inning |
|
inning_topbot |
|
hc_x |
|
hc_y |
|
tfs_deprecated |
|
tfs_zulu_deprecated |
|
fielder_2 |
|
umpire |
|
sv_id |
A date/time stamp of when the PITCHf/x tracking system first detected the pitch in the air, it is in the format YYMMDD_hhmmss. |
vx0 |
The horizontal velocity of the pitch measured at the initial point, in feet per second. |
vy0 |
The forward (towards home plate) velocity of the pitch measured at the initial point, in feet per second. |
vz0 |
The vertical velocity of the pitch measured at the initial point, in feet per second. |
ax |
The horizontal acceleration of the pitch measured at the initial point, in feet per second per second. |
ay |
The forward (towards home plate) acceleration of the pitch measured at the initial point, in feet per second per second. |
az |
The vertical acceleration of the pitch measured at the initial point, in feet per second per second. |
sz_top |
The distance in feet from the ground to the top of the current batter’s rulebook strike zone as measured from the video by the PITCHf/x operator. The operator sets a line at the batter’s belt as he settles into the hitting position, and the PITCHf/x software adds four inches up for the top of the zone. |
sz_bot |
The distance in feet from the ground to the bottom of the current batter’s rulebook strike zone. The PITCHf/x operator sets a line at the hollow of the knee for the bottom of the zone. |
hit_distance_sc |
|
launch_speed |
|
launch_angle |
|
effective_speed |
|
release_spin_rate |
|
release_extension |
|
game_pk |
|
pitcher.1 |
|
fielder_2.1 |
|
fielder_3 |
|
fielder_4 |
|
fielder_5 |
|
fielder_6 |
|
fielder_7 |
|
fielder_8 |
|
fielder_9 |
|
release_pos_y |
|
estimated_ba_using_speedangle |
|
estimated_woba_using_speedangle |
|
woba_value |
|
woba_denom |
|
babip_value |
|
iso_value |
|
launch_speed_angle |
|
at_bat_number |
|
pitch_number |
|
pitch_name |
|
home_score |
|
away_score |
|
bat_score |
|
fld_score |
|
post_away_score |
|
post_home_score |
|
post_bat_score |
|
post_fld_score |
|
if_fielding_alignment |
|
of_fielding_alignment |
test |
* Pitch types from Daktronics.