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Blackmar-Diemer Gambit Accepted: Gunderam Defense

92K games from Lichess · Updated January 2026

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Analyze this line move by move

Black expected score · All ratings · All speeds

51.4%

45%55%
Floor51.1%

the worst score you would still get, 90% confident. At best 51.7%.

Measured over 92K games at this level and clock.

Playablewins about as often as it loses at this level

Roughly even — the middlegame decides more than this opening choice does.

Outcomes for Black

Draw 3.7 · Score = win + ½ of the draws · 92K games

Rank among the families Black can choose here
not ranked — this is a variation, not a family
Games in this context
92K
Best context
54.7% at 2000-2199 Rapid
Worst context
47.3% at 1000-1199 Rapid
Average game length
31 moves
Games that end decisively
96.3%
Draws
3.7%

Best and worst are the strongest and weakest squares with at least 500 games behind them. The table further down shows every square, including thinner ones.

Where it holds · Black score by rating × clock

Green is clearly ahead for Black, grey is around even, red is behind. Tap a cell to measure there, and again to clear. It falls away as the rating rises: 54.5% at 0-999, 46.4% at 2500+.

RatingUBBulleBlitzRapidClass
0-999—
1000-1199
1200-1399
1400-1599
1600-1799
1800-1999
2000-2199
2200-2499—
2500+——

Expected score matrix by rating bracket and time control

  • 0-999 rating, Bullet: 49.5% expected score (596 games)
  • 0-999 rating, Blitz: 48.2% expected score (1,085 games)
  • 0-999 rating, Rapid: 50.3% expected score (388 games)
  • 0-999 rating, Classical: 70.0% expected score (1 games)
  • 1000-1199 rating, UltraBullet: 68.2% expected score (4 games)
  • 1000-1199 rating, Bullet: 49.9% expected score (1,312 games)
  • 1000-1199 rating, Blitz: 48.2% expected score (2,495 games)
  • 1000-1199 rating, Rapid: 47.3% expected score (1,155 games)
  • 1000-1199 rating, Classical: 57.7% expected score (5 games)
  • 1200-1399 rating, UltraBullet: 38.9% expected score (3 games)
  • 1200-1399 rating, Bullet: 50.1% expected score (2,362 games)
  • 1200-1399 rating, Blitz: 51.4% expected score (4,631 games)
  • 1200-1399 rating, Rapid: 48.6% expected score (2,206 games)
  • 1200-1399 rating, Classical: 56.7% expected score (21 games)
  • 1400-1599 rating, UltraBullet: 50.0% expected score (8 games)
  • 1400-1599 rating, Bullet: 50.6% expected score (3,332 games)
  • 1400-1599 rating, Blitz: 52.1% expected score (7,883 games)
  • 1400-1599 rating, Rapid: 50.2% expected score (3,948 games)
  • 1400-1599 rating, Classical: 56.8% expected score (95 games)
  • 1600-1799 rating, UltraBullet: 50.0% expected score (30 games)
  • 1600-1799 rating, Bullet: 51.6% expected score (4,602 games)
  • 1600-1799 rating, Blitz: 51.7% expected score (9,107 games)
  • 1600-1799 rating, Rapid: 51.9% expected score (4,870 games)
  • 1600-1799 rating, Classical: 58.9% expected score (225 games)
  • 1800-1999 rating, UltraBullet: 61.2% expected score (12 games)
  • 1800-1999 rating, Bullet: 51.3% expected score (5,346 games)
  • 1800-1999 rating, Blitz: 53.1% expected score (10,258 games)
  • 1800-1999 rating, Rapid: 53.5% expected score (3,991 games)
  • 1800-1999 rating, Classical: 50.6% expected score (171 games)
  • 2000-2199 rating, UltraBullet: 62.2% expected score (19 games)
  • 2000-2199 rating, Bullet: 50.3% expected score (5,337 games)
  • 2000-2199 rating, Blitz: 52.4% expected score (6,470 games)
  • 2000-2199 rating, Rapid: 54.7% expected score (1,475 games)
  • 2000-2199 rating, Classical: 56.2% expected score (71 games)
  • 2200-2499 rating, Bullet: 50.3% expected score (4,665 games)
  • 2200-2499 rating, Blitz: 51.4% expected score (2,602 games)
  • 2200-2499 rating, Rapid: 52.4% expected score (356 games)
  • 2200-2499 rating, Classical: 50.0% expected score (2 games)
  • 2500+ rating, Bullet: 49.4% expected score (915 games)
  • 2500+ rating, Blitz: 39.8% expected score (283 games)
  • 2500+ rating, Rapid: 50.0% expected score (3 games)

Related Openings

Parent
Blackmar-Diemer Gambit Accepted
50.9%
Variations (5)
Blackmar-Diemer Gambit Accepted: Ryder Gambit
54.2%
Blackmar-Diemer Gambit Accepted: Teichmann Defense
53.2%
Blackmar-Diemer Gambit Accepted: Euwe Defense
58.8%
Blackmar-Diemer Gambit Accepted: Ziegler Defense
55.2%
Blackmar-Diemer Gambit Accepted: Pietrowsky Defense
53.4%
Continuations (1)
Blackmar-Diemer Gambit Accepted: Gunderam Defense, Stader Variation
47.6%
Analyze Blackmar-Diemer Gambit Accepted: Gunderam Defense PositionsSee what each move is worth at your rating, move by move

Methodology

Across every rating and clock, the Blackmar-Diemer Gambit Accepted: Gunderam Defense scores 51.4% for Black — we are 90% confident the real figure is between 51.1% and 51.7% — from 92K Lichess games. Win rate, draw rate and loss rate come from games played December 2023 to November 2025.

How the figures are made
Whose games these are
92K+ rated games played on Lichess (2023-12 to 2025-11). The games are Lichess’s and free for anyone to use. What is ours is the reading of them. Last rebuilt January 2026.
Which games we count
  • Rated games only — nothing casual.
  • Both players within 200 rating points of each other. A mismatch tells you about the gap, not about the opening.
  • At least 2 moves played.
  • A game is filed under White’s rating.
Why every number comes with a range
A number off a few hundred games is a guess. The same number off millions is a fact. The range is what tells them apart, and it is what the lists rank on — so an opening cannot reach the top on a lucky run of forty games. The more games behind a figure, the narrower its range.
How much we need before we say anything
An opening page needs 100 games. A gambit needs 50 games at a rating before we will say whether it pays there. The chaos and trap lists need 500 games overall and 250 games at one rating or clock.

Frequently Asked Questions

What is the Blackmar-Diemer Gambit Accepted: Gunderam Defense win rate?

Playing the Blackmar-Diemer Gambit Accepted: Gunderam Defense, Black wins 49.5%, draws 3.7% and loses 46.8%. Counting a draw as half a point, that is an Expected Score of 51.4%. It rests on 92K rated games from Lichess.

At what rating does the Blackmar-Diemer Gambit Accepted: Gunderam Defense perform best?

The Blackmar-Diemer Gambit Accepted: Gunderam Defense performs best for Black at 1800-1999, with an Expected Score of 52.7% (20K games) and the highest Floor of any rating with enough games to read.

Is the Blackmar-Diemer Gambit Accepted: Gunderam Defense better in blitz or rapid?

For Black, the Blackmar-Diemer Gambit Accepted: Gunderam Defense scores about the same in both: an Expected Score of 51.8% in Blitz (45K games) against 51.4% in Rapid (18K games).

How sharp is the Blackmar-Diemer Gambit Accepted: Gunderam Defense?

The Blackmar-Diemer Gambit Accepted: Gunderam Defense has a sharpness score of 96.3 (very decisive), meaning 96.3% of games end decisively. Average game length is 31 moves.

What is the Blackmar-Diemer Gambit Accepted: Gunderam Defense win rate at 0-999?

At 0-999, Black wins 47.6%, draws 2.7% and loses 49.7%. Counting a draw as half a point, that is an Expected Score of 49.0%. It rests on 2.1K Lichess games, which average 25 moves.

What is the Blackmar-Diemer Gambit Accepted: Gunderam Defense win rate at 1000-1199?

At 1000-1199, Black wins 47.0%, draws 2.9% and loses 50.1%. Counting a draw as half a point, that is an Expected Score of 48.5%. It rests on 5.0K Lichess games, which average 27 moves.

What is the Blackmar-Diemer Gambit Accepted: Gunderam Defense win rate at 1200-1399?

At 1200-1399, Black wins 48.9%, draws 3.0% and loses 48.2%. Counting a draw as half a point, that is an Expected Score of 50.4%. It rests on 9.2K Lichess games, which average 28 moves.

What is the Blackmar-Diemer Gambit Accepted: Gunderam Defense win rate at 1400-1599?

At 1400-1599, Black wins 49.8%, draws 2.9% and loses 47.3%. Counting a draw as half a point, that is an Expected Score of 51.3%. It rests on 15K Lichess games, which average 29 moves.

What is the Blackmar-Diemer Gambit Accepted: Gunderam Defense win rate at 1600-1799?

At 1600-1799, Black wins 50.0%, draws 3.6% and loses 46.4%. Counting a draw as half a point, that is an Expected Score of 51.8%. It rests on 19K Lichess games, which average 31 moves.

What is the Blackmar-Diemer Gambit Accepted: Gunderam Defense win rate at 1800-1999?

At 1800-1999, Black wins 50.7%, draws 3.9% and loses 45.4%. Counting a draw as half a point, that is an Expected Score of 52.7%. It rests on 20K Lichess games, which average 32 moves.

What is the Blackmar-Diemer Gambit Accepted: Gunderam Defense win rate at 2000-2199?

At 2000-2199, Black wins 49.6%, draws 4.4% and loses 46.0%. Counting a draw as half a point, that is an Expected Score of 51.8%. It rests on 13K Lichess games, which average 33 moves.

What is the Blackmar-Diemer Gambit Accepted: Gunderam Defense win rate at 2200-2499?

At 2200-2499, Black wins 48.2%, draws 5.0% and loses 46.8%. Counting a draw as half a point, that is an Expected Score of 50.7%. It rests on 7.6K Lichess games, which average 35 moves.

What is the Blackmar-Diemer Gambit Accepted: Gunderam Defense win rate at 2500+?

At 2500+, Black wins 44.2%, draws 5.8% and loses 50.0%. Counting a draw as half a point, that is an Expected Score of 47.1%. It rests on 1.2K Lichess games, which average 38 moves.

What is the Blackmar-Diemer Gambit Accepted: Gunderam Defense win rate in Bullet?

In Bullet, Black wins 49.1%, draws 3.0% and loses 47.9%. Counting a draw as half a point, that is an Expected Score of 50.6%. It rests on 28K Lichess games.

What is the Blackmar-Diemer Gambit Accepted: Gunderam Defense win rate in Blitz?

In Blitz, Black wins 49.8%, draws 3.8% and loses 46.3%. Counting a draw as half a point, that is an Expected Score of 51.8%. It rests on 45K Lichess games.

What is the Blackmar-Diemer Gambit Accepted: Gunderam Defense win rate in Rapid?

In Rapid, Black wins 49.3%, draws 4.2% and loses 46.5%. Counting a draw as half a point, that is an Expected Score of 51.4%. It rests on 18K Lichess games.

What is the Blackmar-Diemer Gambit Accepted: Gunderam Defense win rate in Classical?

In Classical, Black wins 52.1%, draws 7.5% and loses 40.4%. Counting a draw as half a point, that is an Expected Score of 55.9%. It rests on 591 Lichess games.

Is the Blackmar-Diemer Gambit Accepted: Gunderam Defense a good opening?

The Blackmar-Diemer Gambit Accepted: Gunderam Defense is about level. Across all ratings, Black wins 49.5% of its games and loses 46.8%. It performs best at 1800-1999. Your results depend on your rating, time control, and how well you know the typical plans.