run_expectancy_code: *Generate run expectancy and related measures from Baseball...

In baseballr: Acquiring and Analyzing Baseball Data

Generate run expectancy and related measures from Baseball Savant data

Description

These functions allow a user to generate run expectancy and related measures and variables from Baseball Savant data. Measures and variables will be added to the data frame.

Usage

run_expectancy_code(df, level = "plate appearance")

Arguments

df	A data frame generated from Baseball Savant.
level	Whether you want run expectancy calculated at the plate appearance or pitch level. Defaults to plate appearance.

Value

Returns the input Baseball Savant data frame (the same Statcast pitch-level columns produced by statcast_search() – see that function's return value for the full column-by-column reference) with run-expectancy columns appended. The appended columns are:

col_name	types	description
final_pitch_game	numeric	1 if the row is the last pitch of the game, 0 otherwise.
final_pitch_at_bat	numeric	1 if the row is the last pitch of the plate appearance, 0 otherwise.
runs_scored_on_pitch	numeric	Runs that scored on the pitch (parsed from the play description, plus the batter on a home run).
bat_score_after	numeric	Batting team score after the pitch.
final_pitch_inning	numeric	1 if the row is the last pitch of the half-inning, 0 otherwise.
bat_score_start_inning	numeric	Batting team score at the start of the half-inning.
bat_score_end_inning	numeric	Batting team score at the end of the half-inning.
cum_runs_in_inning	numeric	Cumulative runs scored in the half-inning up to the pitch.
runs_to_end_inning	numeric	Runs scored from the current state to the end of the half-inning.
count_base_out_state	character	Count, outs, and base-occupancy state string (pitch-level run expectancy).
avg_re	numeric	Average run expectancy for the current base-out (or count-base-out) state.
next_count_base_out_state	character	Base-out (or count-base-out) state of the following event.
next_avg_re	numeric	Average run expectancy for the next state (0 at the end of an inning).
change_re	numeric	Change in run expectancy between the current and next state.
re24	numeric	RE24: change in run expectancy plus runs scored on the pitch.

At the plate-appearance level the analogous state columns are named base_out_state and next_base_out_state.

Examples

 try({
   df <- statcast_search(start_date = "2016-04-06", end_date = "2016-04-15", 
                         playerid = 621043, player_type = 'batter') 
   run_expectancy_code(df, level = "plate appearances")
 })

baseballr documentation built on Aug. 27, 2026, 1:07 a.m.