| 1661.7 | 1228.7 | 28 | 36 | Koutsouvelis, M (Matthew) | | ENM | 1749.6 | 1273.9 | 2026 PECC Fast & Furious Blitz I | 7 | 2026-05-21 | B | B | 0 | 0.36 | -0.36 | -2.2 | 0.41 | -0.41 | -14.6 |
| 1661.7 | 1403.8 | 28 | 32 | Koutsouvelis, M (Matthew) | | ENM | 1749.6 | 1184 | 2026 PECC Fast & Furious Rapid | 3 | 2026-04-23 | R | B | 0 | 0.36 | -0.36 | -5.4 | 0.71 | -0.71 | -22.9 |
| 1645.7 | 1643.1 | 20 | 20 | Koutsouvelis, M (Matthew) | | ENM | 1599.2 | 1597.5 | Eastern Cape Inter-Regional Individual Chess Championship 2025 (U12 Open) | 5 | 2025-07-12 | S | W | 0 | 0.6 | -0.6 | -10 | 0.59 | -0.59 | -11.8 |
| 1648.7 | 1646.6 | 20 | 20 | Koutsouvelis, M (Matthew) | | ENM | 1496.9 | 1497.3 | NMBCU Closed 2025 (U12) | 6 | 2025-06-14 | S | B | 1 | 0.63 | 0.37 | 6.1 | 0.63 | 0.37 | 7.4 |
| 1502.7 | 1517.8 | 20 | 20 | Koutsouvelis, M (Matthew) | | ENM | 1492.5 | 1492.9 | NMBCU Open 2025 (C) | 6 | 2025-05-24 | S | W | 1 | 0.55 | 0.45 | 7.5 | 0.57 | 0.43 | 8.6 |
| 1485.5 | 1506.7 | 20 | 20 | Koutsouvelis, M (Matthew) | | ENM | 1449 | 1445.6 | NMB 2nd Trials 2025 (U12) | 6 | 2025-03-08 | S | W | 0 | 0.58 | -0.58 | -9.6 | 0.61 | -0.61 | -12.2 |
| 1445 | 1428.3 | 20 | 20 | Koutsouvelis, M (Matthew) | | ENM | 1390 | 1372.3 | NMBCH Trial 1 2025 (U12) | 3 | 2025-02-15 | S | B | 0 | 0.52 | -0.52 | -8.6 | 0.52 | -0.52 | -10.4 |
