Simon K Williams
GMUnited Kingdomborn 1979FIDE ID 404454
Rating & statistics
FIDE rating lists · Sep 2023 – Sep 20262360
2400
2440
2480
2520
2467 · Sep 2023
Oct
2024
Apr
Jul
Oct
2025
Apr
Jul
Oct
2026
Apr
Jul
Oct
Sep 2023Oct 2026
2467Rapid
2449Classical
2389Blitz
2550peak, Nov 2009
2,952games
1,433wins, 49%
476draws, 16%
1,043losses, 35%
Play style
before facing themWhat you need to know before facing themElite accuracy: 91.3% average
Low resilience (34%): Doesn't save lost positions
Very consistent (87%)
Very precise: only 0.2 blunders/game
Dominates 1.c4 as 
(64% in 196 games)
(64% in 196 games)Vulnerable to 1.b3 
(only 44%)
(only 44%)Play against Williams's Twin
Their real openings, level & style
Practice against a bot that uses their real openings and playing style
Based on 2,952 games
Openings
2,952 gamesBased on 2,952 player gamesWeaknesses
where they slip as ♔ WhiteCaro-Kann1.e4 c6 2.♝c4 d517 games, last played 3 months ago58.8%losses
Sicilian: d6 Systems1.e4 c5 2.♞f3 d617 games, last played 3 weeks ago52.9%losses
Strengths
what holds up for them as ♔ WhiteEnglish: Anglo-Indian1.c4 ♞f6 2.♞c3 g617 games, last played 2 years ago64.7%wins
Queen's Indian1.d4 ♞f6 2.c4 e6 3.♞f3 b629 games, last played last month62.1%wins
Deep analysis
Stockfish · Classical · 208 analyzedStockfish · Classical games · 208 analyzedAccuracy by phase
Opening
94.9%
Middlegame
91.6%
Endgame
93.3%
Clutch factor
+4%Winning (+2)Winning (+2)
93%74g
EqualEqual position
94%48g
Losing (−2)Losing (−2)
89%86g
Accuracy under pressure barely drops when losing.
Problematic pieces
20%
65 err
19%
60 err
17%
56 err
17%
54 err
14%
44 err
13%
43 err
Critical moment
Move 37 avg0%
30%
17%
23%
30%
30% of blunders occur after move 16-25. Keep tension until then.of blunders occur after move 16-25. Keep tension until then.
Error heatmap · Critical squaresError heatmap
15
13
FewMany
110Errors mapped
e5 / g4Hotspot zone
e5
1515 err
g4
1313 err
c5
1111 err
e4
1111 err
f4
1111 err
e5/g4 concentrate most errors. Force decisions in those zones.
e5/g4 concentrate most errors. Force decisions in those zones.
Critical blunders
10 errors · Stockfish#58
♜a3?? vs Henriquez Villagra
Endgame · OTB · 2026
#49
♚a4?? vs Anton Guijarro
Endgame · OTB · 2026
#52
♞c5?? vs Martinez Alcantara
Endgame · OTB · 2026
#45
axb5?? vs Henriquez Villagra
Endgame · OTB · 2026
#61
c5?? vs Shimanov
Endgame · OTB · 2026
#25
fxg4?? vs Theodorou
Middlegame · OTB · 2026
Recent games
2,952 gamesSchilstra, Laurens(2166)
Titled Tue 1st Sep 2026 · 1 Sept 2026
Safin Safarullakhan(2189)
Titled Tue 1st Sep 2026 · 1 Sept 2026
Tilahun , Abel Mathewos(1944)
Titled Tue 1st Sep 2026 · 1 Sept 2026
Bartel, Mateusz(2549)
Titled Tue 1st Sep 2026 · 1 Sept 2026
Steiners, Emils(2139)
Titled Tue 1st Sep 2026 · 1 Sept 2026
Nayak Rajesh(2296)
Titled Tue 1st Sep 2026 · 1 Sept 2026
Endgame statistics
114 endgames (50.4%) · force Double Rook (0%)Unlock Endgame Statistics
All their endgames: discover where they collapse under pressure
Repertoire
PROTime controls · Years · Events
2,952 games in scope
8
76
5
4
3
2
1a
b
c
defghExplore the repertoireevery move played, ranked by frequency
1,455 games50%W16%D34%L
1,455games in this linewon 50%, drew 16%, lost 34%
Move
1. d4
8542w49%1635%
57%1. e4
2412w52%1236%
59%1. c4
1962w55%19%26%
64%1. f4
895m44%1343%
51%1. ♞f3
335w33%42%25%
55%1. b3
181y50%1733%
58%1. g4
52y60%040%
60%1. ♞a3
52y60%040%
60%1. a4
55m60%040%
60%1. b4
22y100%00
100%1. ♞c3
22y050%50%
25%1. a3
113y100%00
100%1. ♞h3
111y100%00
100%1. f3
1Aug 1999100%00
100%1. h4
112m00100%
0%1. g3
110y00100%
0%