Blackmar-Diemer Gambit Accepted: Ryder Gambit

Key ideas for both sides

White

After ...Qxd4, hit the queen with Be3 and follow with O-O-O, so the rook lands on d1 with tempo.
The queen on f3 already points at f7, so Bc4 adds a second attacker there very quickly.
If Black declines the d4 pawn, as in the ...g6 engine line, play Bf4, O-O-O and Bd3 for a direct kingside setup.
Develop the g1 knight to e2 or h3 so it does not block the queen's view down the f-file.

Black

Take the pawn: 5...Qxd4 is the engine's first choice, and after 6.Be3 the queen checks on h4 to provoke g3.
Offer queen trades with ...Qg4 and ...Qf5. With two extra pawns, every trade weakens White's attack.
Develop before grabbing more: ...c6, ...Bg4 or ...Be6, then castle. Greedy queen raids are how the Halosar Trap catches Black.
If you prefer to decline, ...g6 and ...Bg7 keeps a solid king and still leaves White a pawn down.

Plans and pawn structure

If Black takes on d4, White's whole game is speed: Be3, O-O-O, Bc4 or Bd3 and rooks on the d- and f-files, with the queen on f3 or f2 aiming at f7. Black's job is to bring the queen home, finish development and trade pieces. Queen trades on g4 or f5 are welcome for Black. If Black ignores d4 and plays ...g6, White stays one pawn down but gets a free hand, with Bf4 against c7 and long castling, while Black castles short and plays ...c6 and ...Be6.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position −1.61: a large advantage for Black. Its three top choices for Black:

−1.61 5...Qxd4 6.Be3 Qh4+ 7.g3 Qg4 8.Qf2
−1.24 5...a6 6.Nge2 Nc6 7.Bf4 Nxd4 8.Nxd4
−1.24 5...g6 6.Bf4 Bg7 7.O-O-O c6 8.h3

Pawns, from White's side.

How it scores on lichess

1,363 rated lichess games reached this position; White scored 54.4%.

under 120055.6%

1200–159957.2%

1600–199952.6%

2000 and up44.0%

Light: White wins. Grey: draws. Dark: Black wins. About the sample.

Traps and pitfalls

Halosar Trap (White sets it)

In the Blackmar-Diemer Gambit, Black attacks the white queen with 7...Bg4. White ignores it with 8.Nb5, and if Black takes the queen, 9.Nxc7# follows because the rook on d1 controls the open d-file.

The Halosar Trap explained

How to play against it

Take on d4 with the queen. After 6.Be3, check on h4, then offer the queen trade on g4. Keep the queen away from b2 and other queenside raids until your king is safe, since that is Halosar Trap territory once White castles long. White scores 54.4% overall here but only 44% above 2000, so accurate defense pays.

Questions

What are the moves of the Blackmar-Diemer Gambit Accepted: Ryder Gambit?

The Blackmar-Diemer Gambit Accepted: Ryder Gambit starts 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Qxf3. Its ECO code is D00.

Is the Blackmar-Diemer Gambit Accepted: Ryder Gambit good for White?

Stockfish 17.1 rates the position −1.61 at depth 20, which is a large advantage for Black. In 1,363 lichess games from our sample, White scored 54.4%. Only for attackers who accept being two pawns down against a defender who knows ...Qxd4 and the queen trade offers.

What is the main idea of the Blackmar-Diemer Gambit Accepted: Ryder Gambit?

White recaptures with the queen instead of the knight, so the d4 pawn is left hanging. The idea is to give a second pawn for fast development and long castling. Sound defense with ...Qxd4 and early queen trades leaves Black clearly better, so this is a dubious gambit.

What should Black play next?

The engine's first choice is Qxd4, with a6 and g6 close behind. 5...Qxd4 grabs the second pawn and, after Be3, checks on h4 to force g3 and steer toward a queen trade.

Updated October 2026. Sources and method.