Gillingham played 169 league seasons and cup tournaments in the data, 1913 to 2026. 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).
| 774 | RCS Verviétois (Belgium) | 2.7 |
| 775 | Çaykur Rizespor (Turkey) | 2.7 |
| 776 | Avellino (Italy) | 2.7 |
| 777 | Gillingham (England) | 2.7 |
| 778 | Chamois Niortais (France) | 2.7 |
| 779 | Spezia Calcio (Italy) | 2.7 |
| 780 | FK Shamkir (Azerbaijan) | 2.7 |