Koellner, Ruben Gideon

GER GER·Born 2004·FIDE #12993093·2,603 Games

Classical25312,519 Games

Rapid242543 Games

Blitz238441 Games

Play against Koellner, Ruben Gideon's Twin

PRO

Uses their openings, level & style

Practice against a bot that uses their real openings and playing style

Ready to play

2603 games analyzed

Statistics

Total

2603

Wins

1154

Draws

484

Losses

959

44%19%37%

Play Style

What you need to know before facing them

Elite accuracy: 93.1% average

High resilience (62%): Dangerous even when losing

Solid conversion: 89%

Very consistent (88%)

Very precise: only 0.1 blunders/game

Dominates 1.Nf3 ♔ (75% in 16 games)

Vulnerable to 1.Nf3 ♚ (only 37%)

Deep Analysis

Stockfish 18 · Classical games · 542 analyzed

Accuracy by phase

Opening

95.7%

Middlegame

93.3%

Endgame

95.6%

Clutch Factor — Move accuracy when winning vs. equal vs. losing — does their level drop when the game turns against them?

+5%

Winning (+2 or more)

94%236g

Equal position

94%166g

Losing (-2 or more)

90%98g

Performance under pressure

Problematic Pieces — Which pieces cause most errors?

22%

87 errors

22%

89 errors

16%

64 errors

14%

57 errors

13%

51 errors

12%

48 errors

Critical Moment — When does the first serious error occur?

Move 42 average

15%

26%

15%

41%

1-15

16-25

26-35

36-45

46+

41% of blunders occur between move 46+. Keep tension until that moment.

Error Heatmap — Where do most errors occur?

Few

Many

Errors mapped

131

Hotspot zone

e5 / f5

Critical squares

16 err

14 err

13 err

e5/f5 concentrate most errors. Force decisions in those zones.

Openings

Based on player games

Weaknesses

— exploit these lines

No significant weaknesses detected as White

Black72.2%Loses

Reti: Double Fianchetto — 1.Nf3 Nf6 2.g3 d5

18 Games · last played 4 months agoPlay this line

Black52.9%Loses

King's Indian — 1.Nf3 d6 2.d4 Nf6 3.c4 g6

17 Games · last played last yearPlay this line

Strengths

— avoid these lines

No consistent strengths detected as White

Black45.5%Wins

Ruy Lopez: Morphy — 1.e4 e5 2.Nf3 Nc6 3.Bb5 a622 Games · last played 4 months ago

Critical Blunders

10 errors · Stockfish

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#35Qc5??Tacticsvs HansenRapid · 2025

#51Kd6??Endgamevs TeclafRapid · 2025

#22Nb3??Tacticsvs KozulBlitz · 2025

#23Ra5??Tacticsvs GumularzOTB · 2024

#31bxc6??Tacticsvs Dominguez PerezOTB · 2024

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Endgame Statistics

PRO23 endgame categories analyzed

Endgame Statistics

Reveal weaknesses →

23 endgame categories analyzed — discover where they collapse under pressure

Repertoire

Move arrowsmost-played moves

Starting Position

Stockfish

1305 Games

48%18%34%

Move	Games	%
1.d4	1267	57%
1.e4	17	65%
1.Nf3 Strong	16	75%
1.c4 Weak	1	0%
1.d3 Strong	1	100%
1.h4 Strong	1	100%
1.a3 Strong	1	100%
1.c3 Weak	1	0%

MoveGamesPerformance%

1.d4

1267

57%

1.e4

65%

1.Nf3Strong

75%

1.c4Weak

1.d3Strong

100%

1.h4Strong

100%

1.a3Strong

100%

1.c3Weak