PLAYER PAGE
Mari Grobbelaar
2160158380Tshwane (GTP)Personal
Main rating
| Rating | 1379.2 |
| K-factor | 32 |
| Floor | 970.3 |
| Highest | 1490.2 (2026-01-01) |
| Min/Max +/- allowed | 110 |
| Rating Change () | |
| Games | 0 |
| Score | 0 |
| We | 0 |
| SWe | 0 |
| Temp +/- | 0 |
| Penalties | 0 |
| Weight perform | 1290.5 |
| Final +/- | 0 |
| New Rating () | |
| Rating | 1379.2 |
| K-factor | 32 |
| Floor | 970.3 |
| Highest | 1490.2 (2026-01-01) |
| Min/Max +/- allowed | 109.7 |
Standard rating
| Rating | 1377.8 |
| K-factor | 32 |
| Floor | 978 |
| Highest | 1488.2 (2026-01-01) |
| Min/Max +/- allowed | 110 |
| Rating Change () | |
| Games | 0 |
| Score | 0 |
| We | 0 |
| SWe | 0 |
| Temp +/- | 0 |
| Penalties | 0 |
| Weight perform | 1290.5 |
| Final +/- | 0 |
| New Rating () | |
| Rating | 1377.8 |
| K-factor | 32 |
| Floor | 978 |
| Highest | 1488.2 (2026-01-01) |
| Min/Max +/- allowed | 110 |
Rapid rating
| Rating | 1255.4 |
| K-factor | 36 |
| Floor | 755.4 |
| Highest | 1455.5 (2023-09-01) |
| Min/Max +/- allowed | 115.2 |
| Rating Change () | |
| Games | 0 |
| Score | 0 |
| We | 0 |
| SWe | 0 |
| Temp +/- | 0 |
| Penalties | 0 |
| Weight perform | 0 |
| Final +/- | 0 |
| New Rating () | |
| Rating | 1255.4 |
| K-factor | 36 |
| Floor | 755.4 |
| Highest | 1455.5 (2023-09-01) |
| Min/Max +/- allowed | 115.2 |
Blitz rating
| Rating | 1200 |
| K-factor | 36 |
| Floor | 700 |
| Highest | 1200 (2018-10-01) |
| Min/Max +/- allowed | 165.8 |
| Rating Change () | |
| Games | 0 |
| Score | 0 |
| We | 0 |
| SWe | 0 |
| Temp +/- | 0 |
| Penalties | 0 |
| Weight perform | 0 |
| Final +/- | 0 |
| New Rating () | |
| Rating | 1200 |
| K-factor | 36 |
| Floor | 700 |
| Highest | 1200 (2018-10-01) |
| Min/Max +/- allowed | 165.8 |
Rating Graph
Tournaments
| # | Tournament | Type | Start | End | Host | Rounds | Rating | Games | Score | Perform | Rat+/- | Details |
| 1 | 2026 Blou Bull Chess Tournament (U12) | Standard | 2026-02-21 | 2026-02-21 | Tshwane (GTP) | 5 | 1379.2 | 5 | 3 | 1464.8 | 12.2 | Details |
| 2 | 2026 AHS Chess Tournament (U12) | Standard | 2026-02-28 | 2026-02-28 | Tshwane (GTP) | 5 | 1379.2 | 5 | 2.5 | 1248.8 | -19.1 | Details |
| # | Tournament | Type | Start | End | Host | Rounds | Rating | Games | Score | Perform | Rat+/- | Details |
| 1 | 2026 Piet Robbertse Open Chess Tournament (C) | Standard | 2026-02-07 | 2026-02-08 | Tshwane (GTP) | 5 | 1474.2 | 5 | 1 | 1109 | 0 | Details |
| 2 | 2026 Tshwane Chess Registration Tournament (U12-2) | Standard | 2026-01-31 | 2026-01-31 | Tshwane (GTP) | 5 | 1474.2 | 5 | 2.5 | 1287.5 | 0 | Details |
| 3 | 2025 Mzansi Individual Championships (U10 Girls) | Classical | 2025-12-17 | 2025-12-20 | Nelson Mandela Bay (ENM) | 6 | 1376.6 | 6 | 4 | 1458.7 | 0 | Details |
| 4 | 2025 Mzansi Inter Provincial Team Championships (U10 Combined) | Standard | 2025-12-15 | 2025-12-17 | Nelson Mandela Bay (ENM) | 6 | 1376.6 | 6 | 4.5 | 1448 | 0 | Details |
| 5 | Gauteng Inter-Region at Emerald Resort 2025 (U8+U10 Girls) | Standard | 2025-12-06 | 2025-12-07 | Sedibeng (GSV) | 5 | 1376.6 | 5 | 5 | 1673.1 | 0 | Details |
| 6 | 2025 Centurion Chess Open Tournament (U10) | Standard | 2025-09-27 | 2025-09-27 | Tshwane (GTP) | 5 | 1324.7 | 5 | 3.5 | 1628.5 | 0 | Details |
| 7 | 2025 Tshwane South School District CLOSED League Championship (U9A) | Standard | 2025-08-15 | 2025-08-15 | Tshwane (GTP) | 5 | 1346.3 | 5 | 1.5 | 1260.9 | 0 | Details |
| 8 | 2025 Etienne Lewis Closed Chess Tournament (U10) | Standard | 2025-08-08 | 2025-08-10 | Tshwane (GTP) | 7 | 1346.3 | 7 | 3.5 | 1313.2 | 0 | Details |
| 9 | 2025 Wynie Robbertse Chess Tournament (U10) | Standard | 2025-07-19 | 2025-07-19 | Tshwane (GTP) | 5 | 1312.9 | 5 | 2.5 | 1283.8 | 0 | Details |
| 10 | South African Open 2025 (U10 Girls) | Classical | 2025-07-03 | 2025-07-05 | Johannesburg Metro (GJM) | 5 | 1312.9 | 5 | 4 | 1506.9 | 0 | Details |
| 11 | Third Knight Riders Junior Open 2025 (U10) | Standard | 2025-06-22 | 2025-06-22 | Johannesburg Metro (GJM) | 5 | 1311.4 | 5 | 3 | 1326.4 | 0 | Details |
| 12 | 2025 Silver Lakes Chess Club Open Chess Tournament (U10) | Standard | 2025-05-03 | 2025-05-03 | Tshwane (GTP) | 5 | 1311.1 | 5 | 2.5 | 1289.5 | 0 | Details |
| 13 | Lubowski Open 2025 (D2) | Standard | 2025-03-21 | 2025-03-22 | Tshwane (GTP) | 5 | 1355.7 | 5 | 3 | 1302.4 | 0 | Details |
| 14 | 2025 Chris Greyling Open Chess Tournament (U10) | Standard | 2025-03-15 | 2025-03-15 | Tshwane (GTP) | 5 | 1355.7 | 5 | 1.5 | 1105.1 | 0 | Details |
| 15 | Constantiapark Open 2025 (U10) | Standard | 2025-02-15 | 2025-02-15 | Tshwane (GTP) | 5 | 1338.3 | 5 | 4 | 1507.3 | 0 | Details |
| 16 | 2025 Blou Bul Open Chess Tournament (D2) | Standard | 2025-02-08 | 2025-02-08 | Tshwane (GTP) | 5 | 1338.3 | 5 | 2 | 1172.2 | 0 | Details |
| 17 | 2025 Tshwane Chess OPEN Registration Tournament (U10) | Standard | 2025-01-25 | 2025-01-25 | Tshwane (GTP) | 5 | 1318.2 | 5 | 3 | 1401.4 | 0 | Details |
| 18 | Gauteng Inter-Region at UJ 2024 (u10 gIRLS) | Standard | 2024-12-07 | 2024-12-08 | Johannesburg Metro (GJM) | 5 | 1294.2 | 5 | 3 | 1407.4 | 0 | Details |
| 19 | Lardies Ope 2024 (U10) | Standard | 2024-10-26 | 2024-10-26 | Tshwane (GTP) | 5 | 1281.1 | 5 | 3 | 1349.2 | 0 | Details |
| 20 | 2024 Tuks Open Chess Tournament (U10) | Standard | 2024-09-28 | 2024-09-28 | Tshwane (GTP) | 5 | 1277.4 | 5 | 2 | 1271.3 | 0 | Details |
| 21 | 2024 Etienne Lewis (U10) | Standard | 2024-08-30 | 2024-09-01 | Tshwane (GTP) | 7 | 1277.4 | 7 | 4 | 1282.9 | 0 | Details |
| 22 | Menlopark Open Chess Tournament 2024 (U10) | Standard | 2024-07-13 | 2024-07-13 | Tshwane (GTP) | 5 | 1246.3 | 5 | 3.5 | 1416.3 | 0 | Details |
| 23 | 2024 African Youth Chess Championship | Classical | 2024-06-16 | 2024-06-22 | Tshwane (GTP) | 9 | 1309.9 | 9 | 5 | 1221.4 | 0 | Details |
| 24 | 2024 Johannes Mabusela's 40th Birthday Chess Tournament F Section (D) | Standard | 2024-06-01 | 2024-06-01 | Tshwane (GTP) | 5 | 1309.9 | 5 | 2 | 1049.7 | 0 | Details |
| 25 | 2024 Tshwane South School District CLOSED Individual Championships (U11 Girls) | Standard | 2024-05-11 | 2024-05-11 | Tshwane (GTP) | 5 | 1334.2 | 5 | 2 | 1118.6 | 0 | Details |
| 26 | South African Junior Closed Chess Championship 2024 (U8 Girls) | Classical | 2024-04-27 | 2024-05-01 | Ekurhuleni (GE) | 9 | 1334.2 | 9 | 6 | 1369.9 | 0 | Details |
| 27 | 2024 Lubowski Open Chess Tournament (D2) | Standard | 2024-03-23 | 2024-03-24 | Tshwane (GTP) | 5 | 1353.8 | 5 | 3 | 1260 | 0 | Details |
| 28 | 2024 Constantiapark Open (E) | Standard | 2024-02-17 | 2024-02-17 | Tshwane (GTP) | 5 | 1359.2 | 5 | 3 | 1320.6 | 0 | Details |
| 29 | 2024 Tshwane Chess OPEN Registration Tournament (E) | Standard | 2024-01-27 | 2024-01-27 | Tshwane (GTP) | 5 | 1353.2 | 5 | 3.5 | 1323.8 | 0 | Details |
| 30 | 2024 Gauteng Inter-Region Chess Championship (U8+U10 Girls) | Standard | 2024-01-13 | 2024-01-14 | Tshwane (GTP) | 5 | 1353.2 | 4 | 3 | 1438.8 | 0 | Details |
| 31 | Lardies Open Tournament 2023 (F) | Standard | 2023-10-28 | 2023-10-28 | Tshwane (GTP) | 5 | 1251.6 | 5 | 3 | 1323.6 | 0 | Details |
| 32 | 2023 Gauteng Noord (F) | Standard | 2023-10-14 | 2023-10-14 | Tshwane (GTP) | 6 | 1251.6 | 6 | 6 | 1615.6 | 0 | Details |
| 33 | 2023 Centurion Chess Open (E) | Standard | 2023-09-23 | 2023-09-23 | Tshwane (GTP) | 5 | 1234.8 | 5 | 2 | 1162.6 | 0 | Details |
| 34 | 2023 U8 Open Chess Tournament | Rapid | 2023-09-02 | 2023-09-02 | Tshwane (GTP) | 5 | 1234.8 | 5 | 4 | 1447.1 | 0 | Details |
| 35 | 2023 Woman's Day Open Chess Tournament (Pawn) | Standard | 2023-08-09 | 2023-08-09 | Tshwane (GTP) | 5 | 1219.1 | 5 | 3 | 1351.5 | 0 | Details |
| 36 | 2023 Etienne Lewis Closed Tournament (U8) | Standard | 2023-08-26 | 2023-08-26 | Tshwane (GTP) | 6 | 1219.1 | 5 | 2 | 1171.3 | 0 | Details |
| 37 | 2023 Menlo Open Tournament (F) | Standard | 2023-07-22 | 2023-07-22 | Tshwane (GTP) | 5 | 1200 | 5 | 3 | 1316.9 | 0 | Details |
Game statistics ( )
| Games | 0 |
| Wins | 0 |
| Draws | 0 |
| Losses | 0 |
| White | 0 |
| Black | 0 |
| White wins | 0 |
| Black wins | 0 |
| Score | 0 |
| Percent | 0 |
| Dp | 0 |
| AOR | 0 |
| Performance | 0 |
Game statistics ()
| Games | 10 |
| Wins | 3 |
| Draws | 1 |
| Losses | 6 |
| White | 4 |
| Black | 6 |
| White wins | 0 |
| Black wins | 3 |
| Score | 3.5 |
| Percent | 35 |
| Dp | -127.5 |
| AOR | 1325.7 |
| Performance | 1198.2 |
Game statistics (History)
| Games | 199 |
| Wins | 111 |
| Draws | 12 |
| Losses | 76 |
| White | 98 |
| Black | 101 |
| White wins | 56 |
| Black wins | 55 |
| Score | 117 |
| Percent | 58.8 |
| Dp | 74.7 |
| AOR | 1257.4 |
| Performance | 1332.2 |
Rankings (Main)
| National | |
| Overall | 3712 |
| Gender | 585 |
| Age group | 290 |
| Gender/Age | 62 |
| Provincial | |
| Overall | 1271 |
| Gender | 207 |
| Age group | 105 |
| Gender/Age | 19 |
| Regional | |
| Overall | 457 |
| Gender | 88 |
| Age group | 36 |
| Gender/Age | 11 |
Rankings (Standard)
| National | |
| Overall | 3386 |
| Gender | 539 |
| Age group | 277 |
| Gender/Age | 58 |
| Provincial | |
| Overall | 1208 |
| Gender | 196 |
| Age group | 102 |
| Gender/Age | 18 |
| Regional | |
| Overall | 454 |
| Gender | 86 |
| Age group | 37 |
| Gender/Age | 11 |
Rankings (Rapid)
| National | |
| Overall | -1 |
| Gender | -1 |
| Age group | -1 |
| Gender/Age | -1 |
| Provincial | |
| Overall | -1 |
| Gender | -1 |
| Age group | -1 |
| Gender/Age | -1 |
| Regional | |
| Overall | -1 |
| Gender | -1 |
| Age group | -1 |
| Gender/Age | -1 |
Rankings (Blitz)
| National | |
| Overall | -1 |
| Gender | -1 |
| Age group | -1 |
| Gender/Age | -1 |
| Provincial | |
| Overall | -1 |
| Gender | -1 |
| Age group | -1 |
| Gender/Age | -1 |
| Regional | |
| Overall | -1 |
| Gender | -1 |
| Age group | -1 |
| Gender/Age | -1 |
Performance ( )
| Games | 0 |
| Score | 0 |
| Percent | 0 |
| Aor | 0 |
| Dp | 0 |
| Prat | 0 |
Performance ()
| Games | 10 |
| Score | 3.5 |
| Percent | 35 |
| Aor | 1325.7 |
| Dp | -127.5 |
| Prat | 1198.2 |
Performance (12 months)
| Games | 74 |
| Score | 42 |
| Percent | 56.8 |
| Aor | 1300.7 |
| Dp | 57.4 |
| Prat | 1358.1 |
Performance (History)
| Games | 199 |
| Score | 117 |
| Percent | 58.8 |
| Aor | 1257.4 |
| Dp | 74.7 |
| Prat | 1332.2 |
Top 5 opponents most often played
| Type | # | Opponent | Games | White | Black | First tournament | Last tournament | Details |
| Overall | 1 | Westermann, Z (Zelri) | 6 | 1 | 5 | 2023 Gauteng Noord (F) | 2025 Silver Lakes Chess Club Open Chess Tournament (U10) | Details |
| Overall | 2 | Barkhuizen, R (Reuben) | 5 | 2 | 3 | 2023 Etienne Lewis Closed Tournament (U8) | 2025 Tshwane Chess OPEN Registration Tournament (U10) | Details |
| Overall | 3 | Rocher, G (Gideon) | 4 | 3 | 1 | 2023 Menlo Open Tournament (F) | Lardies Open Tournament 2023 (F) | Details |
| Overall | 4 | Roos, B (Benjamin) | 4 | 2 | 2 | 2023 Etienne Lewis Closed Tournament (U8) | 2025 Tshwane South School District CLOSED League Championship (U9A) | Details |
| Overall | 5 | Nawrattel, A (Abigail) | 4 | 1 | 3 | 2023 Gauteng Noord (F) | 2025 Wynie Robbertse Chess Tournament (U10) | Details |
| Standard | 1 | Westermann, Z (Zelri) | 6 | 1 | 5 | 2023 Gauteng Noord (F) | 2025 Silver Lakes Chess Club Open Chess Tournament (U10) | Details |
| Standard | 2 | Barkhuizen, R (Reuben) | 5 | 2 | 3 | 2023 Etienne Lewis Closed Tournament (U8) | 2025 Tshwane Chess OPEN Registration Tournament (U10) | Details |
| Standard | 3 | Rocher, G (Gideon) | 4 | 3 | 1 | 2023 Menlo Open Tournament (F) | Lardies Open Tournament 2023 (F) | Details |
| Standard | 4 | Roos, B (Benjamin) | 4 | 2 | 2 | 2023 Etienne Lewis Closed Tournament (U8) | 2025 Tshwane South School District CLOSED League Championship (U9A) | Details |
| Standard | 5 | Nawrattel, A (Abigail) | 4 | 1 | 3 | 2023 Gauteng Noord (F) | 2025 Wynie Robbertse Chess Tournament (U10) | Details |