Square One
    Opening Walkthrough
    8
    7
    6
    5
    4
    3
    2
    1a
    b
    c
    d
    e
    f
    g
    h
    Opening Coach

    Blackmar-Diemer Gambit

    D00You play white
    1/9
    Your move

    Claim the center and open the c1-bishop's diagonal. The quiet half of a violent plan.

    Your line9 to go

    Play the moves — your line builds here as you go.

    The Blackmar-Diemer Gambit

    You hand over a pawn on move four to open the f-file. Two moves later his queen is eating in your half of the board — and the c7 square is a furnace.

    This is a bet, and you should know the odds before you take it. You throw a pawn with 4.f3 to blast the f-file open, and when he takes you recapture with the QUEEN — 5.Qxf3, played by 53% of this rating band. Stockfish scores that at -1.7 and prefers the quiet 5.Nxf3 (-0.8), so you are paying about a pawn of objective evaluation. What you buy is a queen on f3 aimed at b7 and f7, a bishop wall on e3, and a knight that lands on b5 with the c7 square already smoking. 15% of opponents get greedy and take on d4. When they do, this tree mates them on move nine.

    The line, move by move

    1. d4 d5 2. e4 dxe4 3. Nc3 Nf6 4. f3 exf3 5. Qxf3 Qxd4 6. Be3 Qb4 7. O-O-O Bg4 8. Nb5 Bxf3 9. Nxc7#

    1. 1. d4 (you) Queen-pawn opening. Nothing here says gambit yet.

    2. 1... d5 (opponent) Half of all opponents answer 1.d4 with 1...d5 — 50%. The most symmetrical, most solid reply there is.

    3. 2. e4 (you) e4! Straight into the middle, completely undefended. 68% take it, which is exactly the plan — every pawn he grabs is a file you get to open.

    4. 2... dxe4 (opponent) 68% take. He is a pawn up and you have not developed a piece. Both of those facts are about to stop mattering.

    5. 3. Nc3 (you) Nc3 attacks the pawn on e4. He can't hold it with another pawn, so he has to defend it with a piece or let it go.

    6. 3... Nf6 (opponent) …Nf6 — 58%, the most natural move on the board. It guards e4 and develops. It also puts the knight on the square that will be pinned, chased and abandoned for the rest of this game.

    7. 4. f3 (you) f3!! The whole opening in one move. You are not trying to win the pawn back; you are trying to remove YOUR f-pawn so the f-file opens onto f7. 79% take.

    8. 4... exf3 (opponent) 79% accept. He is two pawns up now. He is also about to face a queen with a clear road to b7.

    9. 5. Qxf3 (you) Qxf3! 53% play this and 46% recapture with the knight instead. The knight move is objectively better by about a pawn. The QUEEN move is the one that points at b7, at f7, and at every greedy idea he is about to have.

    10. 5... Qxd4 (opponent) …Qxd4 — 15% cannot resist. Three pawns is three pawns. But his queen is now standing in the middle of the board on move five with nothing around her.

    11. 6. Be3 (you) Be3! 92% of players find this and it is the whole idea: you develop a piece WITH tempo, hitting her, and the bishop lands on the diagonal that will hold your entire queenside together. She has to move again.

    12. 6... Qb4 (opponent) …Qb4 — 27%, the most popular retreat. It looks active: she pins nothing but eyes b2 and stays out of the way. Look at what she can NOT see from b4: c7.

    13. 7. O-O-O (you) O-O-O! 97% play it and every one of them is right. Your king tucks away, and the rook arrives on d1 covering d7 and d8 — the two squares his king will need in about four moves.

    14. 7... Bg4 (opponent) …Bg4 — 47%, the most common move here by a mile. He develops and attacks your queen at the same time. It is the most natural move in the position and it is the reason he loses.

    15. 8. Nb5 (you) Nb5!! 84% play it. Your queen is attacked and you do not move her. The knight jumps at c7, and c7 is defended by exactly nothing — his queen is on b4, his bishop left c8, and his king is still at home.

    16. 8... Bxf3 (opponent) …Bxf3. 68% take the queen. Of course they do — it is a free queen sitting there and he is already two pawns up. Thirteen thousand games in this database reach this exact position.

    17. 9. Nxc7# (you) Nxc7 — MATE. Count his escape squares: d7 and d8 are covered by the rook you castled onto d1, e7 and f8 are blocked by his own pawn and bishop. Nothing on the board can capture the knight — his queen on b4 has no line to c7. In all 13,024 games from this position, White played Nxc7# 100% of the time.

    Every branch cashes out

    7 coached branches in this family. Engine-checked finishes:

    • Qxd4 / Qb4 / Bxf3Forced mate

      He is two pawns up, he just won your queen, and he is checkmated on move nine. That is the Queen Roast: the queen was never the prize — she was the bait that pulled his bishop off c8 and left c7 alone.

    • Qxd4 / Qb4 / Na6+11.2 by force

      +11.2 and he still has not castled. Queen, rook and knight all came off, and every single trade happened on YOUR terms because his queen spent the opening on b4 doing nothing.

    • Qxd4 / Qb4 / Qxb5+5.4 by force

      +5.4. He traded his queen for a knight because nobody counts the bishop sitting on its starting square. Castling queenside cleared that whole diagonal three moves earlier.

    • Qxd4 / Qe5Forced mate

      He found the one square that defends c7 and he still got mated — on c8, four moves later, because he could not stop taking things. The queen wasn't the trap and the rook wasn't the trap. The greed was.

    • Bg4+10.2 by force

      +10.2. He developed a bishop with tempo on move five and lost his queen on move eight. The b7 pawn was the crack; Nb5 and c7 did the rest.

    • Nc6Sound line

      Dead level at -0.1, and that is a win for you: the calm …Bd7 version leaves him better by 1.3. He tried to trap your queen and handed the whole advantage back in four moves. Not every branch is a bloodbath — some just erase his edge.

    • e6Sound line

      -1.2, and this is the honest number: he defended it correctly, so he is a pawn up with a solid position. What you have is his king castled into an open f-file with his best defender traded off. This is the line where the gambit is a real bet — and it is still the line 27% of your opponents have to find move after move.

    Why it works

    The Blackmar-Diemer is a bet with published odds. You throw the f-pawn to blast the file open, and when Black takes, you recapture with the queen: the Ryder, played by 53 percent of this rating band. Stockfish scores it minus 1.7 and prefers the quiet knight recapture at minus 0.8, so you are paying about a pawn of objective evaluation. What you buy is a queen aimed at b7 and f7, a bishop wall on e3, and a c7 square that this tree calls a furnace.

    Whether c7 burns depends entirely on where Black's queen parks, and that move-order fact is what the whole tree is built on. On b4 she cannot see c7, so after castling long puts your rook on d1, the greedy queen grab Bxf3 meets Nxc7: checkmate on move nine, with every escape square covered by the rook you castled onto d1 or blocked by his own pieces. In the 13,024 database games that reached that position, White played the mate 100 percent of the time. On e5 she covers c7 through d6, and the same knight jump loses on the spot at minus 14.5. So the queen takes b7 instead, and if the taking continues, the mate arrives on c8 four moves later, with his own b8 knight blocking the rook that would have defended it.

    The Queen Roast is the thesis in one line: the queen on f3 was never the prize. She was the bait that pulled his bishop off c8, away from the defence of b7, and left c7 alone. He is two pawns up, he has just won a queen, and he is checkmated.

    How to punish the Blackmar-Diemer Gambit

    The correct defence is also the most popular one, which is rare and worth saying plainly: 5...e6, played 27 percent of the time, shuts the b7 diagonal, frees the bishop, and refuses every pawn on offer. It leaves Black a clean pawn up at minus 1.2 with a solid position, and White playing a genuine attacking game on the open f-file rather than springing a trap. That is the version of the Blackmar-Diemer you should force him into.

    If you have already taken on d4, the saving squares are all mapped. ...Qe5 is the one retreat that covers c7 and switches the mate off. After the b7 grab, ...Qxe3+ holds a level game, and 69 percent find it. In the ...Bg4 line, the rook move that holds is ...Rc8, genuinely level, while the aggressive-looking ...Rb8 loses the queen to a royal fork on c7. Every save follows the same pattern: stop taking, cover c7, give something back.

    How to avoid falling into it

    Every losing branch in this tree is a greed sequence, and each capture buys the next one. Taking the queen on f3 while c7 is bare is checkmate. Taking the rook on d1 after ...Bg4 walks into Qc8 mate on the back rank, where your own b8 knight blocks the defending rook. Taking the b5 knight with the queen forgets the f1 bishop, which has had a clear road to b5 ever since White castled and emptied his back rank. One pawn is a gambit accepted; the third and fourth helpings are how a two-pawns-up position becomes a move nine burial.

    The tell to watch for is O-O-O. The moment White castles long, his rook lands on d1 covering d7 and d8, the two squares your king will need, and every open line toward your uncastled king goes on a timer. Play ...e6 early, keep the queen home or on e5, and make him prove an attack from minus 1.7 instead of proving it for him.

    Questions people actually ask

    Is the Blackmar-Diemer Gambit sound?
    No. The Ryder queen recapture measures minus 1.7 at depth 18, and even the quieter knight recapture is minus 0.8. Against the correct defence, 5...e6, Black is simply a pawn up with a solid position at minus 1.2. The case for it is practical: the punished branches below cover the majority of what club opponents actually play.
    What is the Ryder Gambit?
    The queen recapture 5.Qxf3, offering a second pawn on d4. It is what 53 percent of White players in this data choose over the objectively better Nxf3, because the queen lands pointing at b7 and f7. The 15 percent of opponents who take on d4 walk into the queen hunt this tree is named for.
    How do you refute the Blackmar-Diemer Gambit?
    Decline the second pawn and shut the diagonal: 5...e6 is both the most popular reply and the best one, keeping a clean extra pawn at minus 1.2. If you have taken on d4, park the queen on e5, the one square that defends c7, and be ready to give material back with ...Qxe3+ to reach a level game.
    What happens if Black takes the queen on f3?
    With the black queen on b4 and White castled long, it is checkmate: Nxc7, move nine. The knight cannot be captured, d7 and d8 are covered by the d1 rook, and e7 and f8 are blocked by Black's own pieces. All 13,024 games in the database that reached the position ended with White playing it.
    Does the Nxc7 mate always work in the Blackmar-Diemer?
    No, and knowing when it does not is half the tree. If the queen sits on e5 she defends c7 through d6, and the jump measures minus 14.5: you lose a knight for nothing. The plan switches to Qxb7 against the a8 rook, and mate only returns, on c8, if Black keeps capturing instead of defending.

    Drill the Blackmar-Diemer Gambit against a real opponent

    The trainer above plays every branch with a coach explaining each move. When you are ready, take it into a live game, or paste your Chess.com or Lichess username and see which openings actually cost you rating.

    Play it for realGet your free scout report

    More opening weapons

    New to openings? Learn openings without memorizing explains the approach behind every walkthrough here, and the free AI chess coach guide covers what the rest of the app does without a card.