[Data Bug] db_playerids: four `espn_id` and three `pfr_id` values are each shared by two different players

[f0rthelulz]

Describe the data bug

In files/db_playerids.csv, four espn_id values and three pfr_id values are each attached to two different players (different mfl_id, different name, different birthdate). Same family as #75 / #54 / #42, but on espn_id and pfr_id rather than gsis_id / fantasy_data_id, so I don't think it's covered by those.

Which file is having trouble?

db_playerids.csv, via nflreadpy.load_ff_playerids() (0.1.5, 12,484 rows, pulled 2026-09-01). Reproduces in R:

library(nflreadr); library(dplyr)
ffids <- load_ff_playerids()

ffids |> filter(!is.na(espn_id), !is.na(gsis_id)) |>
  count(espn_id) |> filter(n > 1)          # 4 rows

ffids |> filter(!is.na(pfr_id), !is.na(gsis_id)) |>
  group_by(pfr_id) |> filter(n_distinct(gsis_id) > 1)   # 3 pfr_ids, 6 rows

espn_id shared by two players

espn_id	mfl_id	name	pos	born	gsis_id	pfr_id
16094	11450	Steven Miller	RB	1991-03-23	00-0029885	MillSt00
16094	11797	Marqueston Huff	S	1992-04-06	00-0031059	MillSt00
2516049	12448	Quinton Dunbar	CB	1992-07-22	00-0032007	DunbQu00
2516049	12500	Houston Bates	LB	1991-12-20	00-0032181	BateHo00
2574010	12353	Aaron Ripkowski	RB	1992-12-20	00-0031612	HarrAl00
2574010	12440	Alonzo Harris	RB	1992-11-09	00-0031830	HarrAl00
2582138	12816	David Morgan	TE	1993-05-19	00-0032430	CartKy01
2582138	12683	Kyle Carter	TE	1992-12-17	00-0032606	CartKy01

I can't tell which side of each espn_id pair is correct without an ESPN lookup, so I haven't guessed.

pfr_id shared by two players — and here the id says which one is wrong

Three of the four pairs above also share a pfr_id, and since PFR ids encode the player's own name (Last4First2NN), the incorrect row is identifiable in each case:

pfr_id	belongs to	also (incorrectly) attached to
MillSt00	Steven Miller (mfl 11450)	Marqueston Huff (mfl 11797) — should be HuffMa00
HarrAl00	Alonzo Harris (mfl 12440)	Aaron Ripkowski (mfl 12353) — should be RipkAa00
CartKy01	Kyle Carter (mfl 12683)	David Morgan (mfl 12816)

Expected data

espn_id and pfr_id unique per player where present, as the other id columns are.

Why it matters downstream

Anything building an id crosswalk as a map keyed on espn_id or pfr_id silently keeps whichever row it read last, so a player's data can be attributed to the other player in the pair. All seven pairs here are 2013–16-era players, so the practical impact is small today — I found them because a duplicate-detection check fired, not because anything broke.

Happy to open a PR against files/ if a correction list in the usual format would help.

[f0rthelulz]

Three more rows of the same shape, found 2026-09-03 by diffing db_playerids.csv against nflreadr::load_players() on gsis_id and then resolving every disputed espn_id on ESPN's own athlete endpoint (https://site.web.api.espn.com/apis/common/v3/sports/football/nfl/athletes/<id>), which settles the question the original report left open.

New: a row carrying a different player's ids

mfl_id	name	pos	born	gsis_id	has espn_id / pfr_id	those belong to	should be
11855	Dre Hal	S	1992-05-30	00-0031087	10411 / HallAn01	Andre Hall, RB, South Florida (gsis 00-0023764; mfl 8752 is in the file with no ids)	17467 / HalxAn00
11994	Jacquies Smith	DE	1990-03-18	00-0029112	15256 / DaviBr01	Bryce Davis, LS, Central Oklahoma (gsis 00-0028913, not in the file)	15356 / SmitJa01
16255	Deonte Banks	CB	2001-03-03	00-0039000	42873 / —	ESPN returns no athlete for 42873	4428328

Hal and Smith are the same pattern as the seven pairs above: a near-namesake's ids (Hal / Hall, Davis's 15256 is one digit from Smith's 15356) attached whole, espn_id and pfr_id together. Banks is a lone dead id. pfr_id is correct on Banks already.

And the ESPN side of the original four, resolved. Each shared espn_id belongs to exactly one of its pair; the other row wants the id in the last column. All of these agree with load_players().

espn_id	ESPN says	so the wrong row is	should be
16094	Steven Miller, RB, App State	Marqueston Huff (mfl 11797)	16904
2516049	Quinton Dunbar, CB, Florida	Houston Bates (mfl 12500)	2511350
2574010	Alonzo Harris, RB, Louisiana	Aaron Ripkowski (mfl 12353)	2577467
2582138	Kyle Carter, TE, Penn State	David Morgan (mfl 12816)	2580052

The three pfr_id corrections in the original report stand; Morgan's should be MorgDa01.

Still happy to send this as a PR against files/ if that is easier.