Chess Stalker — Free Chess Opponent Analysis

Analyze any Lichess, Chess.com or FIDE player's openings, weaknesses, blunder patterns and psychological profile. Train against a Twin Bot that replicates your opponent's style. Search by username or FIDE ID across 11 million+ games. Free to use, no signup required.

What you get

Opponent weakness analysis — opening repertoire, common blunders, time pressure patterns
Twin Bot — practice against an AI clone of your opponent's exact playing style
FIDE OTB database — 11 million+ tournament games and 1.7 million+ rated players
Stockfish-powered analysis with depth-25 evaluations
Multi-platform: Lichess, Chess.com, and FIDE in one place
Head-to-head comparison, Nemesis detection, Stalker Score

How it works

Search any Lichess, Chess.com username or FIDE player
Get instant scouting report with weaknesses and patterns
Prepare your strategy and practice against the Twin Bot

GM

Williams, Simon K

ENG ENG·Born 1979·FIDE #404454·2,825 Games

Classical24552,749 Games

Rapid246736 Games

Blitz238940 Games

Statistics

2825

Total

1368

Wins

471

Draws

986

Losses

48%17%35%

Play Style

What you need to know before facing them

Elite accuracy: 93.7% average

Solid conversion: 96%

Very consistent (93%)

Very precise: only 0.0 blunders/game

Dominates 1.g3 ♚ (75% in 10 games)

Vulnerable to 1.b3 ♚ (only 44%)

Deep Analysis

Stockfish 18 · Classical games · 54 analyzed

Accuracy by phase

Opening95.5%

Middlegame93.7%

Endgame95.2%

Clutch Factor

Performance under pressure

+4%

Winning (+2 or more)94%

23 Games

Equal position95%

19 Games

Losing (-2 or more)91%

12 Games

Problematic Pieces

Which pieces cause most errors?

♙

27%

9 errors

♕

27%

9 errors

♞

15%

5 errors

♖

15%

5 errors

♗

12%

4 errors

♔

3%

1 errors

Critical Moment

When does the first serious error occur?

Move 33average

1-15

16-25

26-35

36-45

46+

100% of blunders occur between move 26-35. Keep tension until that moment.

Error Heatmap

Where do most errors occur?

2

1

2

2

1

2

2

2

1

2

abcdefgh

Many

Few

Critical squares

c62 err

d12 err

d32 err

d52 err

e42 err

c6/d1 concentrate most errors. Force decisions in those zones.

Recent Games

L

Galaktionov, Artem2346

Titled Tue 26th May 2026 · 26 May 2026

0-1

L

Siddharth, Jagadeesh2513

Titled Tue 26th May 2026 · 26 May 2026

0-1

W

Sermukhamedova, Adriana2023

Titled Tue 26th May 2026 · 26 May 2026

0-1

W

Al Atarji, Sami2203

Titled Tue 26th May 2026 · 26 May 2026

0-1

W

Fernandez Ramos, Iago2206

Titled Tue 26th May 2026 · 26 May 2026

0-1

W

Povshednyi, Ivan2393

Titled Tue 26th May 2026 · 26 May 2026

1-0

Openings

Based on player games

Weaknesses

EXPLOIT!

White

Caro-Kann

64.3%

14 Games·Loses

1.e4 c6 2.Bc4 d5

1.f4 d5 2.Nf3 Nf6

50.0%

8 GamesLow sample·Loses

1.f4 d5 2.Nf3 Nf6

Black

Sicilian: e6 Systems

61.5%

13 Games·Loses

1.e4 c5 2.Nf3 e6

1.b3 e5 2.Bb2 e4

53.8%

13 Games·Loses

1.b3 e5 2.Bb2 e4

Strengths

AVOID

White

English: Anglo-Indian

64.7%

17 Games·Wins

1.c4 Nf6 2.Nc3 g6

Grünfeld

63.2%

19 Games·Wins

1.d4 Nf6 2.c4 g6 3.Nc3 d5

Black

Sicilian: d6 Systems

46.2%

156 Games·Wins

1.e4 c5 2.Nf3 d6

French: Tarrasch

51.9%

52 Games·Wins

1.e4 e6 2.d4 d5 3.Nd2

Critical Blunders

Tactical errors analyzed with Stockfish

3 errors

▶

#49Bf5??

Endgame

vs Laurent-Paoli

OTB·2026

▶

#32cxd3??

Tactics

vs Korchnoi

OTB·2009

▶

#33Rxd5??

Tactics

vs Korchnoi

OTB·2004

Endgame Statistics

20 endgame categories analyzed — discover where they collapse under pressure

Repertoire

☰ All

♟ Classical

⚡ Rapid

🔥 Blitz

PRO

·

2026

2025

2024

2023

2022

2021

PRO

8

7

6

5

4

3

2

1a

b

c

d

e

f

g

h

Starting Position

1387 Games

50%16%34%

Move	Games	Performance	%
1.d4	812		58%
1.e4	232		58%
1.c4	177		64%
1.f4	86		51%
1.Nf3	36		50%
1.b3	20		58%
1.a4	5		60%
1.Na3	5		60%
1.g4	5		60%
1.b4 Strong	2		100%
1.Nc3 Weak	2		25%
1.a3 Strong	1		100%
1.g3 Weak	1		0%
1.h4 Weak	1		0%
1.Nh3 Strong	1		100%
1.f3 Strong	1		100%

1.d4

58%

812

1.e4

58%

232

1.c4

64%

177

1.f4

51%

86

1.Nf3

50%

36

1.b3

58%

20

1.a4

60%

5

1.Na3

60%

5

1.g4

60%

5

1.b4

100%

2

1.Nc3

25%

2

1.a3

100%

1

1.g3

0%

1

1.h4

0%

1

1.Nh3

100%

1

1.f3

100%

1

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