Event data (cwevent)

cwevent writes one row per event: a plate appearance, a stolen base, a pickoff, a substitution with no play, and so on. It is the richest of the six tools: 97 standard columns plus 67 extended ones.

cwevent -y 2010 -n -f 0,2,3,4,10,14,29,34 2010NYA.EVA

Choosing columns

• -f LIST picks standard columns by number, -x LIST adds extended ones (they come after). Lists are comma-separated and may use ranges: -f 0-6,29,34.
• cwevent -d prints every number and name. The reference has the same list.
• With no -f, you get Chadwick's default set (0-6,8-9,12-13,16-17,26-40,43-45,51,58-61).
• -n writes the column names as a first row. Always use it unless you know the order.

The columns you will use most

-f	Column	Meaning
0	GAME_ID	Retrosheet game ID: home team, date, game number (NYA201004130)
2	INN_CT	inning
3	BAT_HOME_ID	0 = visitors batting, 1 = home team batting
4	OUTS_CT	outs before the play
5, 6	BALLS_CT, STRIKES_CT	count before the play
7	PITCH_SEQ_TX	the pitch sequence as recorded
8, 9	AWAY_SCORE_CT, HOME_SCORE_CT	score before the play
10	BAT_ID	batter
14	PIT_ID	pitcher
26-28	BASE1_RUN_ID, BASE2_RUN_ID, BASE3_RUN_ID	runners on first, second and third
29	EVENT_TX	the play in Retrosheet notation
34	EVENT_CD	numeric event type (below)
36	AB_FL	counts as an at-bat
37	H_CD	hit value: 1 single, 2 double, 3 triple, 4 home run
43	RBI_CT	runs batted in on the play

EVENT_CD values

Code	Event	Code	Event
2	generic out	16	hit by pitch
3	strikeout	17	interference
4	stolen base	18	error
6	caught stealing	19	fielder's choice
8	pickoff	20	single
9	wild pitch	21	double
10	passed ball	22	triple
14	walk	23	home run
15	intentional walk

Choosing games

Option	Effect
-i ID	one game, e.g. -i NYA201004130
-s 0501 -e 0531	only games from May 1 to May 31 (mmdd)
-y YEAR	season whose TEAMyyyy and roster files to use

Several files may be given at once; the header is written once:

cwevent -y 2010 -n -f 0,2,29 2010BOS.EVA 2010NYA.EVA

Output format

Default is quoted, comma-separated text (-a). -ft writes fixed-width Fortran-style output. -Q suppresses the progress messages Chadwick prints to the screen (stderr), which is useful in scripts.

Multi-core processing

When several files are given at once (such as an entire season), chadwickpy automatically runs across multiple CPU cores in parallel, while ensuring the output remains 100% deterministic and byte-for-byte in the exact file order requested.

# Automatically uses all available CPU cores:
cwevent -y 2024 -n 2024*.EV* > 2024_all_events.csv

# Limit or specify the number of worker cores manually:
cwevent -j 4 -y 2024 -n 2024*.EV* > 2024_all_events.csv

# Force single-threaded sequential execution:
cwevent -j 1 -y 2024 -n 2024*.EV* > 2024_all_events.csv

You can also set the default worker count globally using the CHADWICK_JOBS environment variable (e.g. export CHADWICK_JOBS=4).

Good to know

• The first row of data is the first play, not a game header.
• Event files list only one team's home games (2010NYA.EVA has the Yankees at home). Combine all 30 files to get the whole league: cwevent ... 2010*.EV?.
• A column's exact meaning is Chadwick's. See its documentation for details.