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

IM

Taher, Yoseph Theolifus

INA INA·Born 1999·FIDE #7105347·1,431 Games

Classical24511,335 Games

Rapid235231 Games

Blitz237565 Games

Statistics

1431

Total

809

Wins

253

Draws

368

Losses

57%18%26%

Play Style

What you need to know before facing them

Elite accuracy: 91.8% average

High resilience (63%): Dangerous even when losing

Solid conversion: 84%

Very consistent (86%)

Very precise: only 0.1 blunders/game

Dominates 1.d4 ♔ (76% in 234 games)

Vulnerable to 1.Nf3 ♔ (only 31%)

Deep Analysis

Stockfish 18 · Classical games · 336 analyzed

Accuracy by phase

Opening95.4%

Middlegame91.9%

Endgame94.0%

Clutch Factor

Performance under pressure

+5%

Winning (+2 or more)92%

176 Games

Equal position94%

110 Games

Losing (-2 or more)87%

75 Games

Problematic Pieces

Which pieces cause most errors?

♖

22%

125 errors

♕

19%

107 errors

♙

18%

106 errors

♗

14%

78 errors

♔

14%

79 errors

♞

14%

82 errors

Critical Moment

When does the first serious error occur?

Move 42average

1-15

16-25

26-35

36-45

46+

38% of blunders occur between move 46+. Keep tension until that moment.

Error Heatmap

Where do most errors occur?

15

16

19

18

16

16

17

17

19

18

abcdefgh

Many

Few

Critical squares

d419 err

e619 err

f318 err

f618 err

e517 err

d4/e6 concentrate most errors. Force decisions in those zones.

Recent Games

D

Martinez Alcantara, Jose Eduardo2650

3rd 3-0 Thu 28th May 2026 · 28 May 2026

½-½

W

Potapova, Margarita2243

3rd 3-0 Thu 28th May 2026 · 28 May 2026

0-1

L

Xue, Haowen2553

3rd 3-0 Thu 28th May 2026 · 28 May 2026

0-1

L

Movahed, Sina2575

3rd 3-0 Thu 28th May 2026 · 28 May 2026

1-0

W

Nguyen, Ngoc Truong Son2600

3rd 3-0 Thu 28th May 2026 · 28 May 2026

1-0

W

Rustemov, Alexander2525

3rd 3-0 Thu 28th May 2026 · 28 May 2026

1-0

Openings

Based on player games

Weaknesses

EXPLOIT!

White

No significant weaknesses detected as White

Black

Queen's Gambit Declined

62.5%

8 GamesLow sample·Loses

1.d4 d5 2.c4 e6

King's Indian

60.0%

15 Games·Loses

1.d4 Nf6 2.c4 g6

Strengths

AVOID

White

French: Classical

100.0%

10 Games·Wins

1.e4 e6 2.d4 d5 3.Nc3 Nf6

Sicilian: Closed

74.4%

43 Games·Wins

1.e4 c5 2.Nc3 Nc6

Black

Sicilian: d6 Systems

56.3%

16 Games·Wins

1.e4 c5 2.Nf3 d6

Sicilian: e6 Systems

47.6%

21 Games·Wins

1.e4 c5 2.Nf3 e6

Critical Blunders

Tactical errors analyzed with Stockfish

10 errors

▶

#86Kf7??

Endgame

vs Mekhitarian

OTB·2026

▶

#83Kc3??

Endgame

vs Martinez Alcantara

OTB·2026

▶

#31Qd3??

Tactics

vs Xiong

OTB·2026

▶

#14gxh6??

Tactics

vs Martinez Alcantara

OTB·2026

▶

#84Kf3??

Endgame

vs Mahdavi

OTB·2026

▶

#50Bf6??

Endgame

vs Nakamura

OTB·2026

▶

#13Bxc5??

Tactics

vs Khodko

OTB·2026

▶

#48a5??

Endgame

vs Hamidi

OTB·2026

▶

#64Kd6??

Endgame

vs Le Tuan

OTB·2026

▶

#28Rac1??

Tactics

vs Fiorito

OTB·2025

Endgame Statistics

23 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

711 Games

62%16%22%

Move	Games	Performance	%
1.e4 Strong	329		73%
1.d4 Strong	234		76%
1.c4	84		60%
1.Nf3	32		31%
1.g3	26		65%
1.b3 Weak	4		25%
1.f4 Strong	1		100%
1.c3 Weak	1		0%

1.e4

73%

329

1.d4

76%

234

1.c4

60%

84

1.Nf3

31%

32

1.g3

65%

26

1.b3

25%

4

1.f4

100%

1

1.c3

0%

1

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