Chess South Africa Ratings Database

PLAYER PAGE

Personal

Grobbelaar, M (Mari)

Chess SA id

2160158380

FIDE id

14395355

Date of birth

2016-04-20 (U12)

Gender

Female

Region

Tshwane (GTP)

Citizen

RSA

Titles

Chess SA registered

Yes

Last active game

2025-12-20

Personal details last changed

1900-01-01

Junior GPX Games

Junior GPX Points

Item	Main	Standard	Rapid	Blitz
Rating	1490.2	1488.2	1255.4	1200
Raw rating	1470.3	1478	1255.4	1200
Weighted rating	1340.5	1338.4	1255.4	1200
Weighted performance	1490.2	1488.2	0	0
Floor	970.3	978	755.4	700
K-factor	32	32	36	36
Min/Max rating change allowed	112.8	111.6	153.2	165.8
Highest rating	1490.2 2026-01-01	1488.2 2026-01-01	1455.5 2023-09-01	1200 2018-10-01
Highest raw rating	1470.3 2026-01-01	1478 2026-01-01	1255.4 2024-02-01	1200 2024-02-01
Highest weighted rating	1340.5 2026-01-01	1338.4 2026-01-01	1255.4 2025-08-01	1200 2018-10-01
Highest weighted performance	1490.2 2026-01-01	1488.2 2026-01-01	1455.5 2023-09-01	1200 2024-02-01

Prediction
Item	Main	Standard	Rapid	Blitz
Rating change	-9.8	-9.8	0	0
New rating	1480.4	1478.4	1255.4	1200
Analysis
Rating	1490.2	1488.2	1255.4	1200
Raw rating	1470.3	1478	1255.4	1200
Weighted rating	1340.5	1338.4	1255.4
Weighted performance	1490.2	1488.2	0
K-factor	32	32	36	36
Floor	970.3	978	755.4	700
Max/Min rating change allowed	112.8	111.6	153.2	165.8
Games	0	0	0	0
Score	0	0	0	0
Expected score	0	0	0	0
Score-Expected	0	0	0	0
Temp raw +/-	0	0	0	0
Final raw +/-	0	0	0	0
New raw rating	1470.3	1478	1255.4	1200
New weighted rating	1351.8	1350.7	1255.4	1200
New weighted performance	1480.4	1478.4	0	0
Temp new rating	1480.4	1478.4	1255.4	1200
Temp new rating +/-	-9.8	-9.8	0	0
Final new rating +/-	-9.8	-9.8	0	0
New rating	1480.4	1478.4	1255.4	1200
New K-factor	32	32	36	36
New floor	970.3	978	755.4	700

Item	Main	Standard	Rapid
	0	0	0
	62	62	0
	74	74	0
	36	31	5
	0	0	0
	0	0	0
History	172	167	5

Games since
	Main 136	Standard 136		Rapid 0		Blitz 0
Gender	Female
Age group	U10
Region	Tshwane (GTP)
Province	Gauteng (GT)
Main
	RSA		Province		Region
Overall	2439		856		300
Female	430		157		62
U10	174		76		30
U10 Female	25		8		4
Standard
	RSA		Province		Region
Overall	2291		860		326
Female	400		153		66
U10	161		76		32
U10 Female	21		8		4
Rapid
	RSA		Province		Region
Overall	-1		-1		-1
Female	-1		-1		-1
U10	-1		-1		-1
U10 Female	-1		-1		-1
Blitz
	RSA		Province		Region
Overall	-1		-1		-1
Female	-1		-1		-1
U10	-1		-1		-1
U10 Female	-1		-1		-1


	Games	Score	%	Dp	AvgOpp	Performance
Main	0	0	0	0	0	0
Standard	0	0	0	0	0	0
Rapid	0	0	0	0	0	0
Blitz	0	0	0	0	0	0

	Games	Score	%	Dp	AvgOpp	Performance
Main	62	34	54.84	41.1	1299.4	1340.6
Standard	62	34	54.84	41.1	1299.4	1340.6
Rapid	0	0	0	0	0	0
Blitz	0	0	0	0	0	0
History
	Games	Score	%	Dp	AvgOpp	Performance
Main	172	100	58.14	69.2	1252.4	1321.6
Standard	167	96	57.49	63.6	1254.2	1317.8
Rapid	5	4	80	255	1192.1	1447.1
Blitz	0	0	0	0	0	0

Date	Main	Standard	Rapid	Blitz
2026-01-01	1470.3	1478	1255.4	1200
2025-11-30	1376.7	1382.2	1255.4	1200
2025-11-01	1376.7	1382.2	1255.4	1200
2025-09-30	1376.7	1382.2	1255.4	1200
2025-09-01	1324.7	1318.1	1255.4	1200
2025-08-01	1346.3	1340.9	1255.4	1200
2025-07-01	1312.9	1308	1255.4	1200
2025-06-01	1311.4	1305	1255.4	1200
2025-05-01	1311.1	1304.8	1255.4	1200
2025-04-01	1309.5	1302.8	1255.4	1200
2025-03-01	1355.7	1353.9	1255.4	1200
2025-02-01	1338.3	1336.8	1255.4	1200
2025-01-01	1318.2	1318.9	1255.4	1200
2024-12-01	1294.2	1293.3	1255.4	1200
2024-11-01	1281.1	1275.7	1255.4	1200
2024-10-01	1281.1	1275.7	1255.4	1200
2024-09-01	1277.4	1268.9	1255.4	1200
2024-11-01	1277.4	1268.9	1255.4	1200
2024-07-01	1246.3	1227.1	1255.4	1200
2024-06-01	1309.9	1296.6	1255.4	1200
2024-05-01	1334.2	1325.4	1255.4	1200
2024-04-01	1334.2	1325.4	1255.4	1200
2024-03-01	1353.8	1344.5	1255.4	1200
2024-02-01	1359.2	1351.7	1255.4	1200

Comming soon.

Tournaments

History

No tournaments found.

#	Tournament	Start	End	Type	Host	Rounds	Games	Score	Cfr	Analysis

No tournaments found.

#	Tournament	Start	End	Type	Host	Rounds	Games	Score	Cfr	Analysis

Last 500 tournaments since 01 January 2018

#	Tournament	Start	End	Type	Host	Rounds	Games	Score	Cfr	Analysis
1	2025 Mzansi Individual Championships (U10 Girls)	2025-12-17	2025-12-20	Standard	Nelson Mandela Bay (ENM)	6	6	4	Yes	Analysis
2	2025 Mzansi Inter Provincial Team Championships (U10 Combined)	2025-12-15	2025-12-17	Standard	Nelson Mandela Bay (ENM)	6	6	4.5	Yes	Analysis
3	Gauteng Inter-Region at Emerald Resort 2025 (U8+U10 Girls)	2025-12-06	2025-12-07	Standard	Sedibeng (GSV)	5	5	5	Yes	Analysis
4	2025 Centurion Chess Open Tournament (U10)	2025-09-27	2025-09-27	Standard	Tshwane (GTP)	5	5	3.5	Yes	Analysis
5	2025 Tshwane South School District CLOSED League Championship (U9A)	2025-08-15	2025-08-15	Standard	Tshwane (GTP)	5	5	1.5	Yes	Analysis
6	2025 Etienne Lewis Closed Chess Tournament (U10)	2025-08-08	2025-08-10	Standard	Tshwane (GTP)	7	7	3.5	Yes	Analysis
7	2025 Wynie Robbertse Chess Tournament (U10)	2025-07-19	2025-07-19	Standard	Tshwane (GTP)	5	5	2.5	Yes	Analysis
8	South African Open 2025 (U10 Girls)	2025-07-03	2025-07-05	Standard	Johannesburg Metro (GJM)	5	5	4	Yes	Analysis
9	Third Knight Riders Junior Open 2025 (U10)	2025-06-22	2025-06-22	Standard	Johannesburg Metro (GJM)	5	5	3	Yes	Analysis
10	2025 Silver Lakes Chess Club Open Chess Tournament (U10)	2025-05-03	2025-05-03	Standard	Tshwane (GTP)	5	5	2.5	Yes	Analysis
11	Lubowski Open 2025 (D2)	2025-03-21	2025-03-22	Standard	Tshwane (GTP)	5	5	3	Yes	Analysis
12	2025 Chris Greyling Open Chess Tournament (U10)	2025-03-15	2025-03-15	Standard	Tshwane (GTP)	5	5	1.5	Yes	Analysis
13	Constantiapark Open 2025 (U10)	2025-02-15	2025-02-15	Standard	Tshwane (GTP)	5	5	4	Yes	Analysis
14	2025 Blou Bul Open Chess Tournament (D2)	2025-02-08	2025-02-08	Standard	Tshwane (GTP)	5	5	2	Yes	Analysis
15	2025 Tshwane Chess OPEN Registration Tournament (U10)	2025-01-25	2025-01-25	Standard	Tshwane (GTP)	5	5	3	Yes	Analysis
16	Gauteng Inter-Region at UJ 2024 (u10 gIRLS)	2024-12-07	2024-12-08	Standard	Johannesburg Metro (GJM)	5	5	3	Yes	Analysis
17	Lardies Ope 2024 (U10)	2024-10-26	2024-10-26	Standard	Tshwane (GTP)	5	5	3	Yes	Analysis
18	2024 Tuks Open Chess Tournament (U10)	2024-09-28	2024-09-28	Standard	Tshwane (GTP)	5	5	2	Yes	Analysis
19	2024 Etienne Lewis (U10)	2024-08-30	2024-09-01	Standard	Tshwane (GTP)	7	7	4	Yes	Analysis
20	Menlopark Open Chess Tournament 2024 (U10)	2024-07-13	2024-07-13	Standard	Tshwane (GTP)	5	5	3.5	Yes	Analysis
21	2024 African Youth Chess Championship	2024-06-16	2024-06-22	Standard	Tshwane (GTP)	9	9	5	Yes	Analysis
22	2024 Johannes Mabusela's 40th Birthday Chess Tournament F Section (D)	2024-06-01	2024-06-01	Standard	Tshwane (GTP)	5	5	2	Yes	Analysis
23	2024 Tshwane South School District CLOSED Individual Championships (U11 Girls)	2024-05-11	2024-05-11	Standard	Tshwane (GTP)	5	5	2	Yes	Analysis
24	South African Junior Closed Chess Championship 2024 (U8 Girls)	2024-04-27	2024-05-01	Standard	Ekurhuleni (GE)	9	9	6	Yes	Analysis
25	2024 Lubowski Open Chess Tournament (D2)	2024-03-23	2024-03-24	Standard	Tshwane (GTP)	5	5	3	Yes	Analysis
26	2024 Constantiapark Open (E)	2024-02-17	2024-02-17	Standard	Tshwane (GTP)	5	5	3	Yes	Analysis
27	2024 Tshwane Chess OPEN Registration Tournament (E)	2024-01-27	2024-01-27	Standard	Tshwane (GTP)	5	5	3.5	Yes	Analysis
28	2024 Gauteng Inter-Region Chess Championship (U8+U10 Girls)	2024-01-13	2024-01-14	Standard	Tshwane (GTP)	5	4	3	Yes	Analysis
29	Lardies Open Tournament 2023 (F)	2023-10-28	2023-10-28	Standard	Tshwane (GTP)	5	5	3	Yes	Analysis
30	2023 Gauteng Noord (F)	2023-10-14	2023-10-14	Standard	Tshwane (GTP)	6	6	6	Yes	Analysis
31	2023 Centurion Chess Open (E)	2023-09-23	2023-09-23	Standard	Tshwane (GTP)	5	5	2	Yes	Analysis
32	2023 U8 Open Chess Tournament	2023-09-02	2023-09-02	Rapid	Tshwane (GTP)	5	5	4	Yes	Analysis
33	2023 Woman's Day Open Chess Tournament (Pawn)	2023-08-09	2023-08-09	Standard	Tshwane (GTP)	5	5	3	Yes	Analysis
34	2023 Etienne Lewis Closed Tournament (U8)	2023-08-26	2023-08-26	Standard	Tshwane (GTP)	6	5	2	Yes	Analysis
35	2023 Menlo Open Tournament (F)	2023-07-22	2023-07-22	Standard	Tshwane (GTP)	5	5	3	Yes	Analysis

#	Games	Start				End
1	9	Tournament 2024 Gauteng Inter-Region Chess Championship				Tournament 2024 Constantiapark Open
		date 2024-01-13	rnd 3	type Standard	result 1	date 2024-02-17	rnd 1	type Standard	result 1
		Opponent Mcphail, A (Ava)				Opponent Fourie, M (Marchant)
2	7	Tournament 2023 Gauteng Noord				Tournament Lardies Open Tournament 2023
		date 2023-10-14	rnd 1	type Standard	result 1	date 2023-10-28	rnd 1	type Standard	result 1
		Opponent Sahoo, S (Shaurya)				Opponent Roberts, M (Marthinus)
3	5	Tournament Gauteng Inter-Region at UJ 2024				Tournament 2025 Tshwane Chess OPEN Registration Tournament
		date 2024-12-07	rnd 3	type Standard	result 1	date 2025-01-25	rnd 2	type Standard	result 1
		Opponent Wong, K (Kayla)				Opponent Matlou, K (Khumo)

#	Games	Start				End
1	9	Tournament 2024 Gauteng Inter-Region Chess Championship				Tournament 2024 Constantiapark Open
		date 2024-01-13	rnd 3	type Standard	result 1	date 2024-02-17	rnd 1	type Standard	result 1
		Opponent Mcphail, A (Ava)				Opponent Fourie, M (Marchant)
2	7	Tournament 2023 Gauteng Noord				Tournament Lardies Open Tournament 2023
		date 2023-10-14	rnd 1	type Standard	result 1	date 2023-10-28	rnd 1	type Standard	result 1
		Opponent Sahoo, S (Shaurya)				Opponent Roberts, M (Marthinus)
3	5	Tournament Gauteng Inter-Region at UJ 2024				Tournament 2025 Tshwane Chess OPEN Registration Tournament
		date 2024-12-07	rnd 3	type Standard	result 1	date 2025-01-25	rnd 2	type Standard	result 1
		Opponent Wong, K (Kayla)				Opponent Matlou, K (Khumo)

#	Games	Start				End
1	3	Tournament 2023 U8 Open Chess Tournament				Tournament 2023 U8 Open Chess Tournament
		date 2023-09-02	rnd 1	type Rapid	result 1	date 2023-09-02	rnd 3	type Rapid	result 1
		Opponent Jansen Van Vuurnen, C (Clana)				Opponent Roberts, M (Marthinus)
2	1	Tournament 2023 U8 Open Chess Tournament				Tournament 2023 U8 Open Chess Tournament
		date 2023-09-02	rnd 5	type Rapid	result 1	date 2023-09-02	rnd 5	type Rapid	result 1
		Opponent Tredoux, R (Renier)				Opponent Tredoux, R (Renier)

No games found.

#	Games	Start				End

#	Games	Start				End
1	7	Tournament 2023 Gauteng Noord				Tournament Lardies Open Tournament 2023
		date 2023-10-14	rnd 1	type Standard	result 1	date 2023-10-28	rnd 1	type Standard	result 1
		Opponent Sahoo, S (Shaurya)				Opponent Roberts, M (Marthinus)
2	5	Tournament Gauteng Inter-Region at UJ 2024				Tournament 2025 Tshwane Chess OPEN Registration Tournament
		date 2024-12-07	rnd 3	type Standard	result 1	date 2025-01-25	rnd 2	type Standard	result 1
		Opponent Wong, K (Kayla)				Opponent Matlou, K (Khumo)
3	4	Tournament Third Knight Riders Junior Open 2025				Tournament South African Open 2025
		date 2025-06-22	rnd 4	type Standard	result 1	date 2025-07-03	rnd 2	type Standard	result 1
		Opponent Samuel, K (Kenneth)				Opponent Du Toit, S (Sarah-Anne)

#	Games	Start				End
1	7	Tournament 2023 Gauteng Noord				Tournament Lardies Open Tournament 2023
		date 2023-10-14	rnd 1	type Standard	result 1	date 2023-10-28	rnd 1	type Standard	result 1
		Opponent Sahoo, S (Shaurya)				Opponent Roberts, M (Marthinus)
2	5	Tournament Gauteng Inter-Region at UJ 2024				Tournament 2025 Tshwane Chess OPEN Registration Tournament
		date 2024-12-07	rnd 3	type Standard	result 1	date 2025-01-25	rnd 2	type Standard	result 1
		Opponent Wong, K (Kayla)				Opponent Matlou, K (Khumo)
3	4	Tournament Third Knight Riders Junior Open 2025				Tournament South African Open 2025
		date 2025-06-22	rnd 4	type Standard	result 1	date 2025-07-03	rnd 2	type Standard	result 1
		Opponent Samuel, K (Kenneth)				Opponent Du Toit, S (Sarah-Anne)

#	Games	Start				End
1	3	Tournament 2023 U8 Open Chess Tournament				Tournament 2023 U8 Open Chess Tournament
		date 2023-09-02	rnd 1	type Rapid	result 1	date 2023-09-02	rnd 3	type Rapid	result 1
		Opponent Jansen Van Vuurnen, C (Clana)				Opponent Roberts, M (Marthinus)
2	1	Tournament 2023 U8 Open Chess Tournament				Tournament 2023 U8 Open Chess Tournament
		date 2023-09-02	rnd 5	type Rapid	result 1	date 2023-09-02	rnd 5	type Rapid	result 1
		Opponent Tredoux, R (Renier)				Opponent Tredoux, R (Renier)

No games found.

#	Games	Start				End

Top 10 opponents most often played

#	Opponent	Main			Standard			Rapid			Blitz
		Gms	Score	Dp	Gms	Score	Dp	Gms	Score	Dp	Gms	Score	Dp
		Gms	Aor	Prat	Gms	Aor	Prat	Gms	Aor	Prat	Gms	Aor	Prat
1	Westermann ,Z (Zelri)	6	4	141.7	6	4	141.7	0	0	0	0	0	0
1	Westermann ,Z (Zelri)	6	1202.9	1344.5	6	1203.3	1344.5	0	0	0	0	0	0
2	Barkhuizen ,R (Reuben)	5	3	85	5	3	85	0	0	0	0	0	0
2	Barkhuizen ,R (Reuben)	5	1241.9	1326.9	5	1245.2	1326.9	0	0	0	0	0	0
3	Rocher ,G (Gideon)	4	1	-212.5	4	1	-212.5	0	0	0	0	0	0
3	Rocher ,G (Gideon)	4	1323.3	1110.8	4	1334.1	1110.8	0	0	0	0	0	0
4	Roos ,B (Benjamin)	4	1.5	-106.2	4	1.5	-106.2	0	0	0	0	0	0
4	Roos ,B (Benjamin)	4	1295	1188.8	4	1297	1188.8	0	0	0	0	0	0
5	Nawrattel ,A (Abigail)	4	3	212.5	4	3	212.5	0	0	0	0	0	0
5	Nawrattel ,A (Abigail)	4	1261.1	1473.6	4	1244.1	1473.6	0	0	0	0	0	0
6	Erasmus ,T (Trisa)	3	1	-141.7	3	1	-141.7	0	0	0	0	0	0
6	Erasmus ,T (Trisa)	3	1440.1	1298.4	3	1439.7	1298.4	0	0	0	0	0	0
7	Anthonissen ,MV (Mikhael Villem)	3	0	-425	3	0	-425	0	0	0	0	0	0
7	Anthonissen ,MV (Mikhael Villem)	3	1578	1153	3	1580.2	1153	0	0	0	0	0	0
8	Roberts ,MH (Marthinus Hendrik)	3	2	141.7	2	1	0	1	1	425	0	0	0
8	Roberts ,MH (Marthinus Hendrik)	3	1203	1344.6	2	1184.6	1203	1	1200	1628	0	0	0
9	Swart ,E (Eben)	3	1	-141.7	2	1	0	1	0	-425	0	0	0
9	Swart ,E (Eben)	3	1254.3	1112.7	2	1248.1	1254.3	1	1200	829.3	0	0	0
10	Lekalakala ,T (Tshimologo)	2	2	425	2	2	425	0	0	0	0	0	0
10	Lekalakala ,T (Tshimologo)	2	1200.7	1625.7	2	1197.7	1625.7	0	0	0	0	0	0

Norms

No norms achieved.

#	Norm	Tournament	Start	End	Rounds	Games	Score	Details

Ratings

Tournaments

Grand Prix

Statistics

Notifications

PLAYER PAGE

Personal

Grobbelaar, M (Mari)

Ratings

Game statistics

Rankings

Historical performance

Last 24 raw ratings

Rating graph

Tournaments

Top 3 Streaks

Top 10 opponents most often played

Norms