Upset index
Scottish Premiership 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
- 60
- Upsets
- 17
- Upset rate
- 28.3%
- Upset index
- 133
Filters
Odds data: 556,529 matches with a clear favourite between 31 Dec 2015 and 8 Nov 2026.
Biggest upsets
By the winner's pre-match chance (from odds) — lowest first
-
Scottish Premiership
Rangers1
Hibernian2
Winner's pre-match chance 14% · odds 6.50
-
Scottish Premiership
Hibernian0
Kilmarnock1
Winner's pre-match chance 14% · odds 6.50
-
Scottish Premiership
Falkirk FC2
Celtic0
Winner's pre-match chance 18% · odds 5.25
-
Scottish Premiership
Hibernian1
Falkirk FC2
Winner's pre-match chance 21% · odds 4.50
-
Scottish Premiership
Heart of Midlothian2
Falkirk FC5
Winner's pre-match chance 21% · odds 4.50
-
Scottish Premiership
Hibernian1
Motherwell2
Winner's pre-match chance 21% · odds 4.33
Scottish Premiership: by season
The most chaotic and most predictable seasons
Giant killers
Win more than expected as the underdog
| Team | Underdog wins | Expected | Index |
|---|---|---|---|
| Falkirk FC |
5/10 | 2.1 | 143 |
 Dundee FC |
2/6 | 1.1 | 115 |
| Rangers |
1/1 | 0.3 | 114 |
| Hibernian |
1/2 | 0.3 | 113 |
 Aberdeen |
2/6 | 1.3 | 112 |
 St. Johnstone |
2/7 | 1.6 | 108 |
 Dundee Utd |
1/4 | 0.8 | 104 |
| Motherwell |
1/5 | 1.1 | 100 |
 St. Mirren |
1/8 | 1.5 | 94 |
| Kilmarnock |
1/9 | 1.6 | 93 |
Upset victims
Lose more than expected as the favourite
| Team | Losses as favourite | Expected | Index |
|---|---|---|---|
| Hibernian |
4/7 | 1.6 | 138 |
| Falkirk FC |
2/3 | 0.8 | 122 |
| Aberdeen |
2/4 | 0.9 | 120 |
| Heart of Midlothian |
3/9 | 1.9 | 117 |
| St. Mirren |
1/2 | 0.6 | 108 |
| Motherwell |
1/3 | 0.7 | 106 |
| Celtic |
2/13 | 1.9 | 103 |
| Dundee Utd |
1/4 | 1.1 | 100 |
| Rangers |
1/11 | 1.6 | 92 |
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.