AC Siena played 47 league seasons and cup tournaments in the data, 1936 to 2020. Success weighs every finish by how hard that competition was to win; Efficiency is the share of what the club could have won that it did win; Edge compares that with an average participant (×1.00).
| 620 | Berliner FC Dynamo (Germany) | 3.8 |
| 621 | Famalicão (Portugal) | 3.8 |
| 622 | Salernitana (Italy) | 3.8 |
| 623 | AC Siena (Italy) | 3.8 |
| 624 | Crewe Alexandra (England) | 3.8 |
| 625 | St Bernard's (Scotland) | 3.8 |
| 626 | Guaraní de Asunción (PAR) | 3.8 |
More: all clubs of Italy · the world top 200