L2M

Articles

• How To Extract The Last Two Minute Reports
• Updating The Last Two Minute Reports: data through the 2019 NBA Finals

Description

This repository is meant as a way to maintain the Last Two Minute (L2M) reports that the NBA releases for certain NBA games. The clean, processed version of the data can be found in 1-tidy/L2M/L2M.csv while the corresponding R code to create this data is scattered across the 0-data and 1-tidy folders. The 0-data/L2M/ folder hosts the raw data (in pdf form).

Season	Games	Grades per period	Calls per period	IC per period	CC Percentage	INC per period	Bad Calls Percentage	CNC per period
2015	139	11.27	4.82	0.15	97%	1.37	25%	5.08
2016	439	12.88	4.77	0.21	96%	1.66	29%	6.45
2017	428	15.00	4.15	0.08	98%	2.49	39%	8.36
2018	475	19.67	4.14	0.12	97%	2.46	39%	13.07
2019	453	21.30	3.63	0.14	96%	2.54	43%	15.12
2020	389	18.07	3.79	0.15	96%	1.08	25%	13.19
2021	405	17.18	3.85	0.19	95%	0.87	22%	12.47
2022	441	17.53	4.18	0.19	95%	1.18	26%	12.18
2023	474	20.80	4.41	0.16	96%	1.15	24%	15.24

All games with L2M Call Accuracy updated through 2023-06-12

Season	Playoffs	Games	Grades per period	Calls per period	IC per period	CC Percentage	INC per period	Bad Calls Percentage	CNC per period
2015	FALSE	113	10.74	4.84	0.15	97%	1.36	24%	4.54
2015	TRUE	26	13.40	4.74	0.14	97%	1.43	25%	7.23
2016	FALSE	410	12.58	4.81	0.21	96%	1.58	28%	6.18
2016	TRUE	29	17.26	4.12	0.18	96%	2.82	43%	10.32
2017	FALSE	403	14.81	4.14	0.08	98%	2.46	38%	8.21
2017	TRUE	25	18.29	4.18	0.04	99%	3.07	43%	11.04
2018	FALSE	452	19.79	4.14	0.11	97%	2.47	39%	13.18
2018	TRUE	23	17.35	4.12	0.23	94%	2.42	41%	10.81
2019	FALSE	422	21.19	3.66	0.14	96%	2.57	43%	14.97
2019	TRUE	31	22.67	3.33	0.15	95%	2.21	43%	17.13
2020	FALSE	364	17.89	3.80	0.15	96%	1.09	25%	13.01
2020	TRUE	25	20.50	3.67	0.13	96%	1.03	25%	15.80
2021	FALSE	379	17.13	3.82	0.18	95%	0.84	22%	12.48
2021	TRUE	26	17.87	4.26	0.29	93%	1.26	28%	12.35
2022	FALSE	412	17.31	4.16	0.19	95%	1.17	25%	11.98
2022	TRUE	29	21.17	4.47	0.23	95%	1.33	27%	15.37
2023	FALSE	442	20.64	4.40	0.16	96%	1.15	24%	15.09
2023	TRUE	32	23.17	4.58	0.14	97%	1.19	23%	17.39

L2M Call Accuracy updated through 2023-06-12

The process for compiling the L2M dataset is to:

1. Download the raw data, these are broken up into the different years which the NBA has collected L2M:
   • Archived which begins on 1 March 2015 and goes through the 2017 NBA Finals.
   • 2017-18
   • 2018-19 - which changes formats to online only after the 2019 NBA All Star Game (February 21, 2019 is the first). This requires the splashr package to handle scraping of the NBA website.
   • 2019-20 - almost exclusively online with only a few PDF games. Use of the splashr package is required.
   • 2020-21 - no substantial changes from the previous season and all were able to be downloaded with the splashr package.
   • 2021-22 - no substantial changes from the previous season and all were able to be downloaded with the splashr package.
   • 2022-23 - current season and so far no PDFs. splashr package required.
2. Read in the pdf files through the pdftools package:
   • Archived
   • 2017-18
   • 2018-19
   • 2019-20
   • None for 2020-21, 2021-22 and so far none for the 2022-23 season.
3. Download box scores for games from basketball-reference.com for score and rosters to match up committing/disadvantaged players.
   • File depends on .rds files created in step 2 to be present in directory.
4. Combine L2M reports with box score information
   • Raw version which does not include box score info, the csv file
   • Final version which includes box score info, the csv file

Variables

The final output includes the following variables:

• period: period at which point the play occurred
• time: time remaining in the period when play occurred
• call_type: raw call type variable in L2M
• committing: committing player or team of the graded infraction in L2M, may be blank
• disadvantaged: disadvantaged player or team of the graded infraction in L2M, may be blank
• decision: judgment of L2M for the call, could be CC, CNC, IC, INC, or blank where CC = Correct Call, CNC = Correct Non-Call, IC = Incorrect Call, INC = Incorrect Non-Call and blank = not detectable without technology
• comments: L2M comments on the play
• game_details: game details on L2M
• page: page of L2M for pdf, will be NA for scraped data
• file: name of L2M file, will be NA for scraped data
• game_date: game date according to L2M report header
• away_score: away final score from the L2M reports, incomplete variable
• away_team: away team name
• home_score: home final score from the L2M reports, incomplete variable
• home_team: home team name
• call: first part of call_type, this is before the colon in call_type
• type: second part of call_type, this is after the colon in call_type
• date: date of game in YYYY-MM-DD format
• home: home team abbreviation
• away: away team abbreviation
• scrape_time: time that NBA website was scraped for L2M
• stint: stint which indicates when a set of plays roughly occurred, only available for scraped data
• game_id: nba.com url for L2M game, last part of “https://official.nba.com/l2m/L2MReport.html/”
• home_bkref: home team abbreviation according to basketball-reference
• bkref_id: game id for basketball-reference
• nba_game_id: NBA API game ID, based off of game_id
• ref_1: name of first referee for game
• ref_2: name of second referee for game
• ref_3: name of third referee for game
• attendance: attendance for the game
• committing_min: total minutes played by player committing action (note, may be NA because the player did not play and likely an input error from NBA on L2M)
• committing_team: team for committing player
• committing_side: home/away for committing player
• disadvantaged_min: total minutes played by player disadvantaged by action
• disadvantaged_team: team for disadvantaged player
• disadvantaged_side: home/away for disadvantaged player
• type2: consistent format for type of infraction
• time_min: minutes remaining in period
• time_sec: seconds remaining in period
• time2: fractional minutes left (ie 1.9 would be one minute and 54 seconds)
• season: NBA season for which the graded play was a part of, convention is to use the last year of the NBA season so 2015 refers to the 2014-15 Season
• playoff: dummy variable equal to TRUE if the game occurred in the playoffs

And an overview of the changes in L2M reporting is provided in 2-eda/2-through-2019-finals. Further, there is a bit of a how-to for downloading and extracting data on the L2M that is provided in 2-eda/2-how-to-last-two-minutes