| 1606.7 | 1438.4 | 20 | 20 | Van Der Merwe, W (Willem) | | GSV | 1325.9 | 1202 | 2025 Sedibeng Municipality OR Tambo Soncini Chess Finals (Boys) | 5 | 2025-10-18 | R | W | 1 | 0.87 | 0.13 | 1.6 | 0.82 | 0.18 | 3.6 |
| 1493.5 | 1477.2 | 20 | 20 | Van Der Merwe, W (Willem) | | GSV | 1312 | 1303.6 | Laer Volkskool Open 15 Feb 2025 (D) | 3 | 2025-02-15 | S | B | 1 | 0.67 | 0.33 | 5.5 | 0.66 | 0.34 | 6.8 |
| 1479.3 | 1480.9 | 20 | 20 | Van Der Merwe, W (Willem) | | GSV | 1314.6 | 1311.9 | NWU Vaal Open 2023 (D) | 4 | 2023-10-14 | S | B | 1 | 0.65 | 0.35 | 5.8 | 0.65 | 0.35 | 7 |
| 1475.3 | 1477.4 | 20 | 20 | Van Der Merwe, W (Willem) | | GSV | 1317 | 1316.2 | Fonteine Chess Open 2023 (E) | 2 | 2023-09-02 | S | W | 0.5 | 0.73 | -0.23 | -3.8 | 0.73 | -0.23 | -4.6 |
| 1322.1 | 1320.1 | 20 | 20 | Van Der Merwe, W (Willem) | | GSV | 1183.7 | 1177.3 | Hoerskool Overvaal 2022 (D) | 4 | 2022-06-11 | S | B | 0 | 0.62 | -0.62 | -10.3 | 0.62 | -0.62 | -12.4 |
