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2023 Week 14 · Sun, Dec 10, 2023 · GEHA Field at Arrowhead Stadium
Final
BillsBuffalo20
BY 3final margin
ChiefsKansas City17
Buffalo Bills 20 at Kansas City Chiefs 17. Final.
Chiefs -2 upset
The verdict · 2023 Week 14
Buffalo Bills 20, Chiefs 17 — on the last possessions.
It turned at Q4 1:01, 4th and 15, on Patrick Mahomes — 16.9 win-probability points to the Bills on one snap, the largest move of the game.
The snaps that bent it
The biggest swing of the game · Q4 1:01 · 4th and 15
Patrick Mahomes
Bills
(1:01) (Shotgun) 15-P.Mahomes pass incomplete deep right to 87-T.Kelce [56-L.Floyd].
U 49.5 ✓
Chiefs closed -2 and lost outright — an upset against the closing number.
Buffalo Bills 20–17 — decided on the final possessions. Biggest swing: Q4 1:01, Bills +16.9% win probability on one snap.
16.9
win-probability points on one snap
The largest move of the game. The two below are drawn against it.
A.J. EpenesaBillsQ1 11:37(11:37) (Shotgun) 15-P.Mahomes pass short left intended for 25-C.Edwards-Helaire INTERCEPTED by 57-A.Epenesa at BUF 41. 57-A.Epenesa to BUF 47 for 6 yards (15-P.Mahomes).
15.7pts
Deonte HartyBillsQ4 5:41(5:41) (Shotgun) 17-J.Allen pass deep right to 11-D.Harty to KC 40 for 25 yards (27-C.Conner).
13.4pts
What separated them
Giveaways
Bills won this one — 1 giveaway, against Chiefs at 3 giveaways.
Billsthe gap went the way the scoreboard did
Red zone
Chiefs owned this one and still lost it — 2 touchdowns on 3 trips, against Bills at 1 touchdown on 3 trips.
Chiefsthe gap went the other way from the scoreboard
Explosive plays
Bills won this one — 7 chunk plays, against Chiefs at 4 chunk plays.
Billsthe gap went the way the scoreboard did
Staying on schedule
Chiefs owned this one and still lost it — 50% of snaps stayed on schedule, against Bills at 41% of snaps stayed on schedule.
Chiefsthe gap went the other way from the scoreboard
2 other measures were inside a third of the league's own spread — two clubs doing the same thing, so they are not shown.
Drawn from the weekly play-by-play file, which paints on the Monday 4:00 AM ET sync after the game.
The model against the market, the momentum underneath, every drive — scrub to replay it
How the game was won
The model and the market were 2.2 win-probability points apart on the average play, and 10 apart at the widest — with the model the more convinced about Chiefs.
MarketModelmodel higher on Chiefshigher on Bills172 of 182 plays carry both curves
(1:01) (Shotgun) 15-P.Mahomes pass incomplete deep right to 87-T.Kelce [56-L.Floyd].
Swing −16.9 for ChiefsExpected points −2.21 for ChiefsThe model had Bills 3 points higher than the market did.play 177
The solid line is the betting market's home win probability; the dashed line is the play-by-play model's. The shaded band between them is the disagreement — emerald where the model liked the home team more, red where it liked the away team more. Drag across the curve or use arrow keys to replay the game; gold diamonds mark the biggest swings.
Highest-leverage plays
4th · 1:01BUF +17% win prob(1:01) (Shotgun) 15-P.Mahomes pass incomplete deep right to 87-T.Kelce [56-L.Floyd].
1st · 11:37BUF +16% win prob(11:37) (Shotgun) 15-P.Mahomes pass short left intended for 25-C.Edwards-Helaire INTERCEPTED by 57-A.Epenesa at BUF 41. 57-A.Epenesa to BUF 47 for 6 yards (15-P.Mahomes).
4th · 5:41KC +13% win prob(5:41) (Shotgun) 17-J.Allen pass deep right to 11-D.Harty to KC 40 for 25 yards (27-C.Conner).
3rd · 0:38BUF +13% win prob(:38) (Shotgun) 15-P.Mahomes pass short right to 4-R.Rice to KC 48 for 6 yards (47-C.Benford). FUMBLES (47-C.Benford), touched at KC 49, RECOVERED by BUF-7-Ta.Johnson at KC 48.
4th · 8:40BUF +9% win prob(8:40) (Shotgun) 17-J.Allen sacked at BUF 19 for -11 yards (90-C.Omenihu).
4th · 1:05BUF +9% win prob(1:05) (Shotgun) 15-P.Mahomes pass incomplete short left to 87-T.Kelce (91-E.Oliver).
SettledThe modelled figures are the league play-by-play model's, not ours.
How the points landed
The margin ledger
Tyler Bass's 39-yard field goal with 1:57 left in the 4th put Buffalo Bills ahead for good. It was the last score of the day.
3rd8:41Tyler Bass·31-yd field goal31-yard field goalholder S.Martin · snap R.Ferguson+317–7
3rd3:34Rashee Rice·4-yd TD catch4-yard touchdown catchfrom Patrick Mahomesfrom Patrick Mahomes+717–14
4th11:33Harrison Butker·27-yd field goal27-yard field goalholder T.Townsend · snap J.Winchester+317–17
4th1:57Tyler Bass·39-yd field goal39-yard field goalholder S.Martin · snap R.FergusonLead never changed again+320–17
7 scores · bar length is the lead after each one
Down-to-down truth
Situational splits
Billscategory by categoryChiefs
Bills2–6Chiefs
329Total yards346
4.7Yards per play5.6
41%Success rate50%
40%Third-down rate50%
1Red-zone touchdowns2
7Explosive plays4
20First downs20
3Sacks taken1
1Turnovers3
The read
Chiefs ahead 6–2 on categories, including the biggest gap of the duel — sacks taken.
Expected points added, per play
The centre line is an average play. A bar to the right of it is a side that gained more than the situation was worth; a bar to the left is a side that lost ground. All six bars share one scale, ±0.35 points.
Every snapexpected points added per play, all downs
+0.02Bills: +0.02 expected points added per play
−0.06Chiefs: −0.06 expected points added per play
Dropping backexpected points added per dropback
−0.05Bills: −0.05 expected points added per play
−0.14Chiefs: −0.14 expected points added per play
Running itexpected points added per rush
+0.18Bills: +0.18 expected points added per play
+0.17Chiefs: +0.17 expected points added per play
Neither side “wins” volume or play-calling mix, so neither is drawn as a duel: Bills ran 70 snaps at a 69% dropback rate against Chiefs’s 62 at 73%. Red-zone trips: Bills 3, Chiefs 3.
NoteChiefs outgained Bills 346-329 but lost the turnover battle 3-1. That was the game.
Derived from the play-by-play, no model
The Read
10 of 11 readings cleared their snap floor and were tested against four comparisons: this week's whole slate, the team's own season, the week before, and the team's own ordinary spread. Every bar below is set in that team's own week-to-week swing, never in league points — one team's swing runs 1.6 to 3.1 times the entire league's spread.
Nothing cleared the bars. No reading led the week's slate, set a season mark, reversed the week before, or sat two of the team's own standard deviations off their number — which is what most Sundays look like, and is the finding rather than a gap.
The season-grain rooms, pointed at this one game
Was this normal for them?
10 of 12 readings cleared their snap floor. Every deviation below is measured in that team's own game-to-game swing, not in league points — because one game's swing runs from 1.6 to 3.1 times the whole league's spread.
their week-to-week swingall 32 teams
upper band = their week-to-week swing · lower rule = all 32 teams · scale -23 pts to 24 pts
right on their number · −1.7 vs their 17.2%, and they swing ±7.5 week to week (−0.22× that swing) · 45 dropbacks
Chiefs20.8%
right on their number · +2.1 vs their 18.7%, and they swing ±6.4 week to week (+0.33× that swing) · 48 dropbacks
NoteKC's play-action rate was the night's one real departure: 6.7%, 9.4 points below their season mean of 16.1% and 1.3 times their own 7.4-point weekly swing.
The Game Day Roster
Who was out, who dressed and never took a snap, and who was on the field how much. Game-day list and snap counts from the weekly roster and snap feeds. Practice-squad and injured-reserve players are not shown — they were never on the game-day list.
2 players played under 8 snaps, so their shares read as a dash rather than a number.
Expected points are modelled in full PPR, so the “vs expected” column stays in that unit whichever format the pills are set to. Switching the pills changes the points column, not the plane.
The field map
Every snap, where it happened
The whole game as one hundred yards. The Chiefs attack right, the Bills attack left, so a change of possession is a reversal you can see. Reading down is the order the snaps were played — not the clock, so a two-minute drill gets the same room as any other fourteen snaps. This game is final.
Bills←Chiefs→
Q1Q2Q3Q4
P.Mahomes pass−15% win probabilitymoment 1 of 4
(11:37) (Shotgun) 15-P.Mahomes pass short left intended for 25-C.Edwards-Helaire INTERCEPTED by 57-A.Epenesa at BUF 41. 57-A.Epenesa to BUF 47 for 6 yards (15-P.Mahomes).
Q1 11:37 · Chiefs · 2nd & 5 at BUF 30 · gained nothing · -6.34 EP · −15.2% win probability
170 snaps placed · 12 without a recorded yard line, left off the map · 4 marked moments — the largest win-probability swings, one per drive.
The Film Room · post-game
Post-game film: 182 plays across 21 drives, personnel groupings on 170 snaps, the eleven on the field by name, manual charting on 177. Everything here paints once the weekly sync ingests the game — there is no live play-level feed in this product, so nothing on this page updates while a game is being played.
Possession by possession
The field rail
7 of 21 drives ended in points. The longest march was KC moving 75 yards from the KC 25 for a touchdown. Each bar is the ground a drive actually covered; KC attacks right, BUF attacks left. Hatching marks a trip inside the twenty.
Every snap
Play stream
182 of 182 plays
Team
Quarter
Down
Play type
Expected points added
Event
Charted
Plays shown
182
EPA per play
-0.06
Success rate
41%
Yards
673
Who was on the field
Personnel groupings
Offensive grouping on every pass and run. A group needs five snaps in this game before it gets a number — under that the sample is a coin flip and the cell reads a dash instead. Open any play above to see the eleven men who were actually on the field for it.
Chiefs1 RB, 1 TE, 3 WR36-0.1681%
Bills1 RB, 1 TE, 3 WR33-0.0376%
Chiefs1 RB, 2 TE, 2 WR21-0.0462%
Bills1 RB, 2 TE, 2 WR21+0.0162%
Bills2 RB, 1 TE, 2 WR7+0.4043%
Chiefs0 RB, 1 TE, 4 WR3——
Bills0 RB, 2 TE, 3 WR2——
Bills1 RB, 1 TE, 2 WR2——
Bills1 RB, 0 TE, 3 WR2——
Bills2 RB, 1 TE, 1 WR1——
Bills1 RB, 3 TE, 1 WR1——
Bills1 RB, 2 TE, 1 WR1——
Chiefs0 RB, 2 TE, 3 WR1——
Chiefs1 RB, 3 TE, 1 WR1——
snapsepapass rate
182 plays · ranked by the win probability each one moved
Every play
Ball
When
Play
Only
Who
182 plays
Bar length is win probability the play moved
1st quarter42 plays
How the play was built
Nobody in motion.
A designed throw, the target set before the snap, it should have been intercepted.
FormationPistolOffense on the fieldOne quarterback, one back, two tight ends and two receiversDefense on the fieldFour linemen, two linebackers and five backsRoute runSwingCoverageCover 1, man with a free safetyMan or zoneManIn the boxSix defendersRushing the passerFourPressure (charted)The passer was kept cleanTime to throw1.9 seconds
Intercepted9 plays, from the Chiefs 25 to the Bills 30
Punt5 plays, from the Bills 47 to the Chiefs 40
Punt6 plays, from the Chiefs 12 to the Chiefs 30
Bills6Chiefs0
Bills7Chiefs0
Touchdown7 plays, from the Bills 47 to the Chiefs 25
Punt6 plays, from the Chiefs 25 to the Chiefs 28
The period ended8 plays, from the Bills 27 to midfield
2nd quarter53 plays
Bills13Chiefs0
Bills14Chiefs0
Touchdown7 plays, from the Chiefs 23 to the Chiefs 6
Punt11 plays, from the Chiefs 25 to the Bills 37
Intercepted9 plays, from the Bills 7 to the Bills 43
Bills14Chiefs6
Bills14Chiefs7
Touchdown15 plays, from the Chiefs 48 to the Bills 7
The period ended11 plays, from the Bills 25 to the Chiefs 44
3rd quarter38 plays
Bills17Chiefs7
Field goal13 plays, from the Bills 25 to the Chiefs 13
Bills17Chiefs13
Bills17Chiefs14
Touchdown11 plays, from the Chiefs 25 to the Bills 4
Punt5 plays, from the Bills 26 to the Bills 33
How the play was built
A man in motion.
Thrown on the first read.
FormationShotgunOffense on the fieldOne quarterback, one back, one tight end and three receiversDefense on the fieldFour linemen, two linebackers and five backsRoute runCurlCoverageCover 4, quartersMan or zoneZoneIn the boxFive defendersRushing the passerFourPressure (charted)The passer was kept cleanTime to throw1.5 seconds
Fumble lost5 plays, from the Chiefs 26 to the Chiefs 42
The period ended4 plays
4th quarter49 plays
Punt1 play
Bills17Chiefs17
Field goal8 plays, from the Chiefs 41 to the Bills 10
Punt10 plays, from the Bills 25 to midfield
Punt4 plays, from the Chiefs 31 to the Chiefs 34
How the play was built
A man in motion.
Thrown on the first read.
FormationShotgunOffense on the fieldOne quarterback, one back, one tight end and three receiversDefense on the fieldThree linemen, two linebackers and six backsRoute runDeep outCoverageCover 1, man with a free safetyMan or zoneManIn the boxSix defendersRushing the passerThreePressure (charted)The passer was pressuredTime to throw2.9 seconds
Bills20Chiefs17
Field goal13 plays, from the Bills 31 to the Chiefs 21
How the play was built
A man in motion.
Thrown on the first read, the ball was not catchable.
FormationShotgunOffense on the fieldOne quarterback, one back, one tight end and three receiversDefense on the fieldFour linemen, one linebacker and six backsRoute runDigCoverageCover 4, quartersMan or zoneZoneIn the boxSix defendersRushing the passerFourPressure (charted)The passer was pressuredTime to throw3.6 seconds
The period ended10 plays, from the Chiefs 25 to the Bills 49
The period ended3 plays
Win probability is the league play-by-play model, 98.5% of plays · a dash means none was published
The cards are drawn from the play-by-play sync, not live, and each one says so on its face.
Closing number vs result
Betting context
Closing spread
Chiefs -2
Closing total
49.5
Bills moneyline
+105
Chiefs moneyline
-125
Chiefs closed -2 and lost outright — an upset against the closing number.
Total closed 49.5; the game landed 37 — under by 12.5.
Conditions and crew
Game environment
Venue
GEHA Field at Arrowhead Stadium
Roof / surface
outdoors · grass
Kickoff weather
Cold, 43°F at kickoff; a light breeze at 7 mph out of the west; overcast.
Referee
Carl Cheffers
Rest
Bills 14 days · Chiefs 7 days
Coaches
Sean McDermott vs Andy Reid
4th · 2:06
BUF +9% win prob
(2:06) (Shotgun) 17-J.Allen pass short left to 86-D.Kincaid to KC 21 for 1 yard (38-L.Sneed) [51-M.Danna].
4th · 10:42KC +9% win prob(10:42) (Shotgun) 17-J.Allen pass deep left to 28-L.Murray to BUF 47 for 21 yards [54-L.Chenal]. FUMBLES, touched at 50, ball out of bounds at 50. Kansas City challenged the pass completion ruling, and the play was Upheld. The ruling on the field stands. (Timeout #1.)
