KNSB FIDE
WK

Willem de Koster

Rated since January 2023

1834 Rapid

RIVALRY

Not enough games to determine rivalries yet.

The good & the bad

Best wins
BODAAN, A. (TON) 1978
12070 Rapidtoernooi SV Voorburg Groep A · Saturday 15 November 2025
STELT VAN DER, E. (EZRA) 1858
10471 Tata Steel Chess Tournament 2026 Weekendvierkampem · Friday 16 January 2026
MUGGE, I.E. (IB) 1806
13663 HSB competitie 2025-2026 April2026 · Tuesday 21 April 2026
KORVER DE, L. (LENNARD) 1578
12070 Rapidtoernooi SV Voorburg Groep A · Saturday 15 November 2025
KOEN SIMONIDES 1442
12070 Rapidtoernooi SV Voorburg Groep A · Saturday 15 November 2025
Worst losses
BOCK DE, G.P.L. (GIJSBERT) 1826
10471 Tata Steel Chess Tournament 2026 Weekendvierkampem · Saturday 17 January 2026
KROON, B. (BART) 1839
12070 Rapidtoernooi SV Voorburg Groep A · Saturday 15 November 2025
KONING DE, A. (AARON) 1853
10471 Tata Steel Chess Tournament 2026 Weekendvierkampem · Sunday 18 January 2026
MACHIEL VAN SOEST 1975
12070 Rapidtoernooi SV Voorburg Groep A · Saturday 15 November 2025
LEE, J.B. (JUNGBIN) 2011
12070 Rapidtoernooi SV Voorburg Groep A · Saturday 15 November 2025
Tata Steel Chess Tournament 2026 Weekendvierkampem Friday 16 January 2026 +1–2=0 -13.1
2026 Chess.com Botwinnik Open Vierkampen Friday 2 January 2026 +0–0=2 +3.6
Rapidtoernooi SV Voorburg Groep A Saturday 15 November 2025 +4–3=0 -3.0
KNSB competitie 2025-2026 Klasse 6 ronde 5 Saturday 20 September 2025 +1–0=0 +1.0
HSB competitie 2025-2026 April2026 Monday 1 September 2025 +1–0=0 +12.8
HSB competitie 2025-2026 CompMrt2026 Monday 1 September 2025 +0–0=1 -0.4
HSB competitie 2025-2026 HSBCompetitieFeb26 Monday 1 September 2025 +0–0=1 +2.0
HSB competitie 2025-2026 November comp Monday 1 September 2025 +0–0=1 -2.8

Rating History

Loading rating history...

Peak Ratings

Classic 1840 May 1, 2026
Rapid 1834 Dec. 1, 2025
Blitz 1827 April 1, 2026

Games

Wins 7
Losses 5
Draws 5
Win Rate 41%

Performance by Color

Color Wins Draws Losses Win Rate
White 4 3 2 44%
Black 3 2 3 38%

Recent Matches

Mugge, I.E. (Ib) (1806) Tuesday 21 April 2026 WIN +12.8
Oole, A.M. (Albert) (1312) Saturday 28 March 2026 WIN +1.0
Toorn van der, A.J. (Aat) (1816) Wednesday 11 March 2026 DRAW -0.4
Okita, R. (Ryoga) (1875) Thursday 12 February 2026 DRAW +2.0
Koning de, A. (Aaron) (1853) Sunday 18 January 2026 LOSS -13.8
Bock de, G.P.L. (Gijsbert) (1826) Saturday 17 January 2026 LOSS -14.9
Stelt van der, E. (Ezra) (1858) Friday 16 January 2026 WIN +15.5
Houten van, A.C.J. (Arno) (1896) Sunday 4 January 2026 DRAW +2.5
Rijnders, W. (Wijnand) (1862) Friday 2 January 2026 DRAW +1.1
Lee, J.B. (Jungbin) (2011) Saturday 15 November 2025 LOSS -8.0
Bodaan, A. (Ton) (1978) Saturday 15 November 2025 WIN +20.3
Korver de, L. (Lennard) (1578) Saturday 15 November 2025 WIN +5.4
Kroon, B. (Bart) (1839) Saturday 15 November 2025 LOSS -14.6
Koen Simonides (1442) Saturday 15 November 2025 WIN +2.5
Machiel van Soest (1975) Saturday 15 November 2025 LOSS -9.3
Bohner, T. (Thomas) (1284) Saturday 15 November 2025 WIN +0.8
Roeleveld, P. (Patrick) (1769) Monday 10 November 2025 DRAW -2.8