Upset index
Upset index
Matches won by the side the pre-match odds gave little chance, and which leagues and teams produce more upsets than expected. Index 100 = as many upsets as expected.
- Matches with a clear favourite
- 461
- Upsets
- 83
- Upset rate
- 18.0%
- Upset index
- 89
Biggest upsets this week
Last 7 days, all sports
Biggest upsets this season
Current season of each competition, by odds
Filters
Odds data: 554,877 matches with a clear favourite between 31 Dec 2015 and 5 Nov 2026.
Biggest upsets
By the winner's pre-match chance (from odds) — lowest first
-
UEFA Youth League
Bodo/Glimt U192
Lille U191
Winner's pre-match chance 5.4% · odds 17.00
-
Scottish Championship
Partick Thistle2
Greenock Morton3
Winner's pre-match chance 9.0% · odds 10.00
-
UEFA Conference League
Lincoln Red Imps1
HNK Hajduk Split0
Winner's pre-match chance 9.4% · odds 10.00
-
Primera División
Nacional Asunción0
Sportivo San Lorenzo2
Winner's pre-match chance 10% · odds 9.00
-
HNL
NK Rudeš1
GNK Dinamo Zagreb0
Winner's pre-match chance 11% · odds 8.50
-
Primera División
Sportivo San Lorenzo2
Libertad1
Winner's pre-match chance 12% · odds 8.00
-
BSC Young Boys
3–5
FC Zürich
-
AC Milan
0–2
Ferencváros TC
-
KF Teuta Durrës
0–1
FK Partizani
-
Atalanta
0–3
Parma
-
Villarreal
0–1
Espanyol
-
Guangxi Hengchen FC
1–2
Wuxi Wugou
-
Red Arrows
0–1
Nkwazi
-
Sarpsborg 08
2–4
Kristiansund BK
-
Cusco FC
0–1
Sport Boys
-
Swedru All Blacks United FC
1–2
Ashanti Gold
-
Fenerbahçe
1–2
Göztepe
-
Mushuc Runa SC
2–3
Manta FC
-
Yongin City FC
4–2
Seoul E-Land FC
-
Sivasspor
1–2
Boluspor
-
Falkirk FC
2–0
Celtic
-
Cuiabá
1–2
São Bernardo
-
Lusitano Ginásio Clube
0–1
Vitória Sernache
-
Deltras FC
0–2
De Red FC
-
Huddersfield Town Women
1–2
Middlesbrough W.F.C.
-
Real Oviedo
2–3
UD Las Palmas
-
Independiente Santa Fé
3–4
Olimpia
-
Fenerbahçe
3–2
Liverpool FC
-
Inter San Carlos
2–3
CD Escorpiones Belen
-
Al-Wahda FC
1–2
Al Khaldiya
-
KAS Eupen
1–2
Virton
-
FC Rapperswil-Jona
1–4
Stade Nyonnais
-
Gimnasia y Tiro de Salta
0–1
Quilmes Atlético Club
-
St.Louis City
0–1
San Diego FC
-
CD Riestra Reserve
2–4
Quilmes Reserve
-
Academia de Balompié Boliviano
2–3
CD San Antonio
-
Emelec
0–2
Leones del Norte
-
Detroit City FC
1–2
Hartford Athletic
-
Oldham Athletic
0–1
Crawley Town
-
Kuching City
2–0
Gangwon FC
Upset index by league
100 = as many upsets as the probabilities predict; above is more chaotic, below more predictable
Giant killers
Win more than expected as the underdog
| Team | Underdog wins | Expected | Index |
|---|---|---|---|
 Vasco da Gama · Campeonato Brasileiro Série A |
1/3 | 0.6 | 107 |
How is it calculated?
- Probability: From pre-match 1X2 (or two-way) odds, with the bookmaker margin removed proportionally: p = (1/odds) / Σ(1/odds). The same formula as the stats hub's “upsets by odds” block.
- Clear favourite and upset: Only matches with at least a 10-point gap between the home and away win probabilities count; if the favourite's opponent wins, it is an upset. Draws are not upsets. Winner's chance of 25% or less = big upset.
- Ranking: The lower the winner's pre-match chance, the bigger the upset (surprise score = 100 × (1 − chance)).
- Index: 100 × (actual upsets + 5) / (expected upsets + 5); expected = sum of the underdogs' win probabilities. The +5 pulls small samples towards 100. Teams have two directions: giant killing (winning as the underdog) and fragility (losing as the favourite).
- Calibration: Expected values are scaled by the source's overall hit factor (0.95 in this view), so a systematic bias of the source does not shift every league the same way.
- Historical (model): For past matches without odds, the probability comes from our learning Elo model replaying the full history chronologically and taking its state before the match (both teams need at least 15 matches; friendlies excluded). Never mixed with odds.