Upset index
Liga Portugal 2 upset index
Including the years before odds: the biggest upsets in history, the most chaotic seasons and the giant killers by our learning Elo model's pre-match probabilities. Index 100 = as many upsets as expected.
- Matches with a clear favourite
- 3,901
- Upsets
- 922
- Upset rate
- 23.6%
- Upset index
- 112
Filters
Model data: 2,476,630 matches with a clear favourite between 26 Apr 1970 and 7 Nov 2026 (learning Elo, pre-match state).
Biggest upsets
By the winner's pre-match chance (Elo model) — lowest first
-
Liga Portugal 2
Famalicão2
FC Porto B4
Winner's pre-match chance 13%
-
Liga Portugal 2
Famalicão1
SC Braga B2
Winner's pre-match chance 13%
-
Liga Portugal 2
Feirense1
Varzim SC2
Winner's pre-match chance 13%
-
Liga Portugal 2
Chaves1
Portimonense SAD2
Winner's pre-match chance 13%
-
Liga Portugal 2
Portimonense SAD1
UD Oliveirense2
Winner's pre-match chance 13%
-
Liga Portugal 2
SC Praiense0
Leixões SC1
Winner's pre-match chance 13%
-
Arouca
2–3
FC Porto B
-
Académica Coimbra
1–2
Varzim SC
-
Famalicão
2–3
Benfica B
-
Paços de Ferreira
0–1
UD Oliveirense
-
Rio Ave
1–2
Académico Viseu FC
-
Feirense
0–2
SC Covilhã
-
B-SAD
0–2
UD Oliveirense
-
Santa Clara
1–2
Académico Viseu FC
-
Feirense
1–2
SC Braga B
-
Benfica B
1–2
Varzim SC
-
Leixões SC
0–1
SC Covilhã
-
Tondela
0–3
CD Aves
-
Real
0–1
Arouca
-
Santa Clara
0–1
Trofense
-
CD Aves
0–1
Clube Oriental de Lisboa
-
Paços de Ferreira
0–1
FC Porto B
-
Moreirense
0–1
UD Oliveirense
-
Feirense
1–2
Atletico CP
-
Real
1–2
Sporting CP B
-
Naval 1893
0–2
SC Braga B
-
Varzim SC
0–1
UD Oliveirense
-
Sporting CP B
2–3
Vitória SC B
-
Gil Vicente
0–1
AD Carregado
-
Benfica B
0–1
Freamunde
-
UD Oliveirense
3–2
Feirense
-
UD Oliveirense
0–2
CD Nacional
-
FC Porto B
0–1
Atletico CP
-
CD Mafra
1–2
SC Covilhã
-
Trofense
1–2
B-SAD
-
CS Marítimo
1–2
UD Oliveirense
-
Estoril
1–2
Boavista
-
Chaves
0–1
CD Aves
-
FC Porto B
0–2
Freamunde
-
Gil Vicente
1–2
Varzim SC
Liga Portugal 2: by season
The most chaotic and most predictable seasons
Giant killers
Win more than expected as the underdog
| Team | Underdog wins | Expected | Index |
|---|---|---|---|
 Torreense |
8/15 | 4.1 | 152 |
| Chaves |
19/51 | 13.3 | 146 |
| FC Porto B |
55/173 | 43.2 | 142 |
| CD Nacional |
14/38 | 9.7 | 142 |
| CD Aves |
22/67 | 16.5 | 141 |
 Penafiel |
53/182 | 45.8 | 130 |
 Gondomar |
4/11 | 2.5 | 126 |
 Vizela |
14/45 | 11.8 | 125 |
| Académica Coimbra |
17/59 | 14.6 | 125 |
| Sporting CP B |
23/80 | 20.4 | 124 |
Upset victims
Lose more than expected as the favourite
| Team | Losses as favourite | Expected | Index |
|---|---|---|---|
| Real |
8/14 | 3.4 | 163 |
| Boavista |
5/7 | 1.8 | 152 |
 Cova da Piedade |
12/31 | 8.3 | 140 |
| Atletico CP |
12/33 | 8.5 | 138 |
| Académico Viseu FC |
45/148 | 37.9 | 132 |
| Feirense |
48/179 | 42.2 | 128 |
 União de Leiria |
19/63 | 16.3 | 126 |
| FC Porto B |
39/142 | 34.8 | 126 |
 Vilaverdense FC |
3/6 | 1.6 | 126 |
| Benfica B |
47/169 | 42.3 | 125 |
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 (0.86 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.