| 2338.2 | 2351.2 | 16 | 16 | Klaasen, CJ (Calvin John) | FM | WCT | 2201.5 | 2227.4 | 2026 South African Closed Chess Championships (Open) | 8 | 2026-02-26 | S | B | 0 | 0.62 | -0.62 | -9.9 | 0.6 | -0.6 | -9.6 |
| 2325.6 | 2329.2 | 20 | 20 | Klaasen, CJ (Calvin) | FM | WCT | 2204.8 | 2230.1 | South African Closed Chess Championship 2024 (Open) | 9 | 2024-03-31 | S | W | 0.5 | 0.68 | -0.18 | -3.6 | 0.66 | -0.16 | -3.2 |
| 2224.1 | 2253.9 | 20 | 20 | Klaasen, CJ (Calvin) | FM | WCT | 2189.4 | 2198 | CKC Invitational Masters 2023 | 2 | 2023-06-10 | S | B | 0.5 | 0.5 | 0 | 0 | 0.52 | -0.02 | -0.4 |
| 2256.7 | 2277.3 | 20 | 20 | Klaasen, CJ (Calvin) | FM | WCT | 2185.3 | 2195 | Cape Town Open 2023 (Championship) | 2 | 2023-03-25 | S | W | 0.5 | 0.62 | -0.12 | -2.3 | 0.64 | -0.14 | -2.8 |
| 2265.7 | 2288.3 | 20 | 20 | Klaasen, CJ (Calvin) | FM | WCT | 2187.7 | 2197.2 | Cape Town Masters Challenge 2023 (IM Norm) | 4 | 2023-01-05 | S | B | 1 | 0.55 | 0.45 | 9 | 0.56 | 0.44 | 8.8 |
| 2306.8 | 2309.1 | 20 | 20 | Klaasen, CJ (Calvin) | FM | WCT | 2226.7 | 2237.9 | 2022 South African Closed Chess Championships (Open) | 6 | 2022-05-11 | S | W | 0.5 | 0.64 | -0.14 | -2.8 | 0.62 | -0.12 | -2.4 |
| 2304.6 | 2307.5 | 20 | 20 | Klaasen, CJ (Calvin) | FM | WCT | 2194.4 | 2207.1 | WP Open 2021 (Championship) | 4 | 2021-05-09 | S | B | 0.5 | 0.59 | -0.09 | -1.6 | 0.58 | -0.08 | -1.6 |
| 2327.6 | 2333.3 | 20 | 20 | Klaasen, CJ (Calvin) | FM | WCT | 2197 | 2209.8 | 2020 Western Province Open (Championship) | 6 | 2020-03-08 | S | W | 0.5 | 0.69 | -0.19 | -3.3 | 0.69 | -0.19 | -3.8 |
| 2369.1 | 2369.1 | 20 | 20 | Klaasen, CJ (Calvin) | FM | WCT | 2228.6 | 2239.6 | 2019 South African Closed Chess Championships (Open A) | 3 | 2019-12-09 | S | W | 1 | 0.71 | 0.29 | 5.8 | 0.69 | 0.31 | 6.2 |
| 2203.8 | 2222.6 | 20 | 20 | Klaasen, CJ (Calvin) | FM | WCT | 2247.9 | 2254.1 | 2019 Capablanca Chess Festival (RR IM Norm) | 2 | 2019-04-19 | S | B | 0.5 | 0.41 | 0.09 | 1.8 | 0.42 | 0.08 | 1.6 |
| 2215.5 | 2223.6 | 20 | 20 | Klaasen, CJ (Calvin) | FM | WCT | 2260.8 | 2260.8 | Graham Solomon Memorial 2018 (Rapid) | 3 | 2018-11-24 | R | W | 0 | 0.49 | -0.49 | -5.9 | 0.5 | -0.5 | -10 |
| 2215.5 | 2223.6 | 20 | 20 | Klaasen, CJ (Calvin) | FM | WCT | 2260.8 | 2241.3 | Graham Solomon Memorial 2018 (Blitz) | 5 | 2018-11-25 | B | W | 0 | 0.49 | -0.49 | -2.5 | 0.52 | -0.52 | -10.4 |
| 2202 | 2202 | 20 | 20 | Klaasen, Cj (Calvin) | FM | WP | 2247 | 2247 | 2017 South African Closed Chess Championships (Open) | 8 | 2017-12-16 | S | W | 0.5 | 0.44 | 0.06 | 1.2 | 0.06 | 0.44 | 8.8 |
| 2215 | 2215 | 20 | 20 | Klaasen, Cj (Calvin) | FM | WP | 2218 | 2218 | 2017 Western Province League (Premier) | 5 | 2017-08-12 | S | B | 0 | 0.5 | -0.5 | -10 | -0.5 | 0.5 | 10 |
| 2166 | 2166 | 20 | 20 | Klaasen, Cj (Calvin) | FM | WP | 2189 | 2189 | 2017 Pss Capablanca (Rr Im Norm) | 4 | 2017-04-28 | S | B | 0.5 | 0.47 | 0.03 | 0.6 | 0.03 | 0.47 | 9.4 |
| 2172 | 2172 | 20 | 20 | Klaasen, Cj (Calvin) | FM | WP | 2160 | 2160 | 2016 African Chess Lounge (Im Norm) | 5 | 2016-11-30 | S | B | 0 | 0.52 | -0.52 | -10.4 | -0.52 | 0.52 | 10.4 |
| 2115 | 2115 | 20 | 20 | Klaasen, Cj (Calvin) | FM | WP | 2113 | 2113 | Sa Closed 2015 (Open A) | 5 | 2015-12-16 | S | B | 0.5 | 0.5 | 0 | 0 | 0 | 0.5 | 10 |
| 2077 | 2077 | 20 | 20 | Klaasen, Cj (Calvin) | FM | WP | 2147 | 2147 | Cape Of Good Hope Open Prestige Section | 3 | 2015-01-24 | S | B | 0 | 0.4 | -0.4 | -6.6 | -0.4 | 0.4 | 8 |
| 2012 | 2012 | 20 | 20 | Klaasen, Cj (Calvin) | | WP | 2127 | 2127 | Manyanani Chess Festival 2014 Prestige Section | 7 | 2014-06-16 | S | W | 0.5 | 0.34 | 0.16 | 3.2 | 0.16 | 0.34 | 6.8 |
| 2005 | 2005 | 20 | 20 | Klaasen, Cj (Calvin) | | WP | 2120 | 2120 | Steinitz Open 2014 (Prestige A) | 1 | 2014-05-09 | S | W | 1 | 0.34 | 0.66 | 13.2 | 0.66 | 0.34 | 6.8 |
| 1836 | 1836 | 20 | 20 | Klaasen, Cj (Calvin) | NM | WP | 2142 | 2142 | Western Province Open 2013 Premier Section | 2 | 2013-03-09 | S | W | 0.5 | 0.14 | 0.36 | 7.2 | 0.36 | 0.14 | 2.8 |
