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

Fedorchuk, Sergey A.

UKR UKR·Born 1981·FIDE #14102536·3,527 Games

Classical25933,104 Games

Rapid2596232 Games

Blitz2530191 Games

Statistics

3527

Total

1771

Wins

1187

Draws

562

Losses

50%34%16%

Play Style

What you need to know before facing them

Elite accuracy: 94.5% average

High resilience (59%): Dangerous even when losing

Solid conversion: 93%

Very consistent (90%)

Very precise: only 0.0 blunders/game

Dominates 1.e4 ♔ (73% in 1738 games)

Deep Analysis

Stockfish 18 · Classical games · 631 analyzed

Accuracy by phase

Opening97.1%

Middlegame94.0%

Endgame95.6%

Clutch Factor

Performance under pressure

+6%

Winning (+2 or more)95%

230 Games

Equal position96%

208 Games

Losing (-2 or more)89%

62 Games

Problematic Pieces

Which pieces cause most errors?

♕

24%

69 errors

♖

21%

61 errors

♙

16%

45 errors

♗

15%

42 errors

♞

12%

35 errors

♔

11%

32 errors

Critical Moment

When does the first serious error occur?

Move 39average

1-15

16-25

26-35

36-45

46+

47% of blunders occur between move 26-35. Keep tension until that moment.

Error Heatmap

Where do most errors occur?

13

14

9

13

11

13

7

7

11

9

abcdefgh

Many

Few

Critical squares

f614 err

d613 err

e413 err

f513 err

d311 err

f6/d6 concentrate most errors. Force decisions in those zones.

Recent Games

W

Shchekachev, Andrei2462

Luc Winants Mem 2026 · 9 May 2026

0-1

W

Vincenti, Leonardo2247

Luc Winants Mem 2026 · 9 May 2026

1-0

W

Ahn, Maximilian1974

Luc Winants Mem 2026 · 9 May 2026

0-1

D

Vrolijk, Liam2517

Luc Winants Mem 2026 · 9 May 2026

½-½

W

Decoster, Frederic2231

Luc Winants Mem 2026 · 9 May 2026

1-0

D

Maerevoet, Sim2456

Luc Winants Mem 2026 · 9 May 2026

½-½

Openings

Based on player games

Weaknesses

EXPLOIT!

White

No significant weaknesses detected as White

Black

No significant weaknesses detected as Black

Strengths

AVOID

White

Sicilian: d6 Systems

60.2%

337 Games·Wins

1.e4 c5 2.Nf3 d6

French: Tarrasch

57.1%

191 Games·Wins

1.e4 e6 2.d4 d5 3.Nd2

Black

Sicilian: e6 Systems

54.8%

250 Games·Wins

1.e4 c5 2.Nf3 e6

Reti: Double Fianchetto

72.2%

36 Games·Wins

1.Nf3 Nf6 2.g3 b5

Critical Blunders

Tactical errors analyzed with Stockfish

10 errors

▶

#36Qf6??

Tactics

vs Royal

OTB·2025

▶

#52Nf4??

Endgame

vs Pultinevicius

OTB·2025

▶

#45Ke4??

Endgame

vs Seemann

OTB·2025

▶

#23Qc2??

Tactics

vs Milov

OTB·2025

▶

#38Nf3??

Tactics

vs Deodhar

OTB·2025

▶

#26Qh2??

Tactics

vs Bellahcene

Rapid·2025

▶

#39Rf8??

Tactics

vs Garrigue

OTB·2025

▶

#33Qb4??

Tactics

vs Gaehwiler

OTB·2025

▶

#32Kf1??

Tactics

vs Haba

OTB·2024

▶

#29Rd7??

Tactics

vs Diermair

OTB·2024

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

1795 Games

57%31%12%

Move	Games	Performance	%
1.e4 Strong	1742		73%
1.c4	35		59%
1.d4	12		63%
1.Nf3 Strong	6		83%

1.e4

73%

1742

1.c4

59%

35

1.d4

63%

12

1.Nf3

83%

6

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