Chess Openings Lab
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Blackmar-Diemer Gambit: Rasa-Studier Gambit

The Rasa-Studier Gambit is 4.Be3, protecting d4 with the bishop before playing f3. White wants to open the f-file with the d4 pawn already secure, while Black can use the extra tempo to defend e4 with ...Bf5 or set up ...e6 and ...b6.

Moves
1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.Be3
ECO
D00
Engine
−0.97 · a clear edge for Black (Stockfish 17.1, depth 20)
Played
174 games in our lichess sample
White scores
46.8%

Key ideas for both sides

White

  • f3 is the follow-up; after ...e6 and fxe4 White gets the pawn back and opens lines.
  • Qd2 and long castling fit well with the bishop on e3, and the d4 pawn stays protected.
  • a3 in the second engine line takes b4 away from Black's pieces before White commits to f3.

Black

  • 4...Bf5 is the engine's first choice; it guards e4 so f3 can be met by ...e6 and calm trades on e4.
  • ...Ng4 hits the e3 bishop and can win the bishop pair if White is careless.
  • ...e6, ...b6 and ...Bb7 pile on e4 and keep a firm grip on the long diagonal.

Plans and pawn structure

The bishop on e3 holds d4 but blocks the e-file and can be harassed by ...Ng4. White aims for f3, Qd2, O-O-O and pressure on the f-file. Black chooses between holding e4 with ...Bf5 and returning the pawn with trades on e4 to get a lead in development. With pieces traded, Black's sounder structure and quicker kingside castling make life easy.

Where the engine's main line heads: White pawn d4, no e-pawns for White, no d-pawn for Black. White has a pawn on d4 and no e-pawn; Black has no d-pawn. White has more central space; Black's pieces are free and the d4 pawn is a target.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position −0.97: a clear edge for Black. Its three top choices for Black:

  1. −0.97 4...Bf5 5.f3 e6 6.fxe4 Nxe4 7.Nxe4
  2. −0.72 4...e6 5.a3 b6 6.f3 Bb7 7.fxe4
  3. −0.71 4...c6 5.f3 exf3 6.Nxf3 Bf5 7.Bd3

Pawns, from White's side.

How it scores on lichess

174 rated lichess games reached this position; White scored 46.8%.

under 120044.7%
1200–159960.0%
1600–199937.5%

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

How to play against it

Answer 4.Be3 with 4...Bf5 and meet f3 with ...e6. If White takes on e4, trade pieces there and play for a comfortable middlegame. Watch for chances to hit the bishop with ...Ng4. White scored only 46.8% overall in this line, so solid moves are enough.

Questions

What are the moves of the Blackmar-Diemer Gambit: Rasa-Studier Gambit?

The Blackmar-Diemer Gambit: Rasa-Studier Gambit starts 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.Be3. Its ECO code is D00.

Is the Blackmar-Diemer Gambit: Rasa-Studier Gambit good for White?

Stockfish 17.1 rates the position −0.97 at depth 20, which is a clear edge for Black. A rare move-order trick for White that gives up time; Black is comfortable with simple development.

What is the main idea of the Blackmar-Diemer Gambit: Rasa-Studier Gambit?

White delays f3 to protect d4 with the bishop first. That reduces Black's ...Qxd4 tricks after f3, but gives Black a free move such as ...Bf5 to defend e4.

What should Black play next?

The engine's first choice is Bf5, with e6 and c6 close behind. 4...Bf5 defends e4 at once so White's f3 push meets a solid ...e6.

Updated October 2026. Sources and method.