Matchday 6 · Premier League 2015-16 · September 19, 2015
Chelsea 2–0 Arsenal: who deserved to win?
Chelsea beat Arsenal 2–0, and the replays back it up: with the way both teams played, Chelsea win 7 of 10, 2 end level. Chelsea made the better chances: 1.6 expected goals to 0.8. An own goal helped Chelsea.
Replay with same day's form
Luck index +23 Chelsea about even · −23 Arsenal
Each team’s own shots from this match, resampled into new matches 4,000 times, each a goal at its expected-goals chance: with the way both teams actually played, how often does this performance win? How the replay works
Ten replays. Chelsea win 7, 2 end level, Arsenal win 1.
- 1 CHE 1 ARS 0
- 2 CHE 2 ARS 1
- 3 CHE 2 ARS 1
- 4 CHE 2 ARS 0
- 5 CHE 2 ARS 0
- 6 CHE 3 ARS 0
- 7 CHE 5 ARS 1
- 8 CHE 1 ARS 1
- 9 CHE 2 ARS 2
- 10 CHE 0 ARS 1
The narrowest view of luck
The same match, with only the coin flips re-rolled: every shot kept where and how it was taken, its outcome redrawn at its chance (75% of finishing counts as luck), own goals at the league’s rate.
Only coin-flips re-rolled
There is no betting line for this match, and no forecast from before kickoff: matches of past seasons are replayed, not forecast.
How 4,000 replays of the 90 minutes ended
Chelsea win 67%, 21% end level, Arsenal win 12%. The line is what actually happened: Chelsea by 2.
Show as a table
| After 90 minutes in the replays | Share of replays |
|---|---|
| Chelsea by 3+ | 18.9% |
| Chelsea by 2 | 21.2% |
| Chelsea by 1 | 26.4% |
| Draw | 21.1% |
| Arsenal by 1 | 9.2% |
| Arsenal by 2 | 2.5% |
| Arsenal by 3+ | 0.5% |
Where the luck was
| Finishing | Shots | Goals | Expected goals | Above expected |
|---|---|---|---|---|
 Chelsea | 23 | 1 | 1.64 | −0.64 |
 Arsenal | 10 | 0 | 0.84 | −0.84 |
Own goals aren’t shots, so they’re counted on their own. A side above expected finished better than its chances, or met a goalkeeper on a bad day; 75% of the gap counts as luck (why that share).
The big chances, and every goal
| Minute | Chance | xG |
|---|---|---|
| 31' | Pedro Eliezer Rodríguez Ledesma didn’t score from a shot | 0.40 |
| 52' | Kurt Happy Zouma scored from a shot | 0.20 |
| 91' | Theo Walcott didn’t score from a shot | 0.34 |
When it happened
Chelsea’s chance of winning
Numbers mark the biggest luck moments, listed below.
| # | When | What happened | Win probability for |
|---|---|---|---|
| 1 | 28' | Theo Walcott didn’t score from a shotFinishing · 5% chance | +1% CHE |
| 2 | 31' | Pedro Eliezer Rodríguez Ledesma didn’t score from a shotFinishing · 40% chance | +10% ARS |
| 3 | 39' | Francesc Fàbregas i Soler didn’t score from a shotFinishing · 7% chance | +2% ARS |
| 4 | 42' | Pedro Eliezer Rodríguez Ledesma didn’t score from a shotFinishing · 5% chance | +1% ARS |
| 5 | 45' | Pedro Eliezer Rodríguez Ledesma didn’t score from a shotFinishing · 5% chance | +1% ARS |
| 6 | 49' | Alexis Alejandro Sánchez Sánchez didn’t score from a free kickFinishing · 8% chance | +3% CHE |
| 7 | 52' | Kurt Happy Zouma scored from a shotFinishing · 20% chance | +25% CHE |
| 8 | 59' | Alexis Alejandro Sánchez Sánchez didn’t score from a shotFinishing · 10% chance | +3% CHE |
Adjust the assumptions
Think finishing is more skill than we do? Change how much of it counts as luck and the coin-flip replay of the 90 minutes reruns in your browser.
Only coin-flips re-rolled
Chelsea 58% · draw 24% · Arsenal 18%
- Final margin
- Chelsea by 2
- Luck in goals
- 1.1 for Chelsea
- Luck-adjusted margin
- Chelsea by 0.9
- Replay with same day's form
- Chelsea 67% · draw 21% · Arsenal 12% unchanged: why
About these numbers
Expected goals per shot from StatsBomb’s open data; the replays, the in-game win probability and the luck shares are our own models, fitted and tested on every shot of four full league seasons and four tournaments, these matches included (methodology and validation). Chelsea win 77% of replays (a draw counted as half).
More from matchday 6, 2015-16
- Stoke 2–2 Leicester Sep 19, 2015 · drawn; replay 25% draws
- Newcastle 1–2 Watford Sep 19, 2015 · replay 54% for Watford
- Aston Villa 0–1 West Brom Sep 19, 2015 · replay 62% for West Brom
- Man City 1–2 West Ham Sep 19, 2015 · replay 29% for West Ham
- Bournemouth 2–0 Sunderland Sep 19, 2015 · replay 67% for Bournemouth
- Swansea 0–0 Everton Sep 19, 2015 · drawn; replay 24% draws
- Southampton 2–3 Man United Sep 20, 2015 · replay 48% for Man United
- Liverpool 1–1 Norwich Sep 20, 2015 · drawn; replay 12% draws
- Tottenham 1–0 Crystal Palace Sep 20, 2015 · replay 61% for Tottenham