The Blackmar-Diemer Gambit is a chess opening that starts with the moves 1. d4 d5 2. e4!?, where White sacrifices a pawn to gain control of the center and open lines for their pieces. The gambit was first introduced by Armand Blackmar and Emil Josef Diemer in the early 20th century, and it has been a popular choice for aggressive players ever since.
One of the variations of the Blackmar-Diemer Gambit is the Ryder Gambit, which occurs after the moves 1. d4 d5 2. e4 dxe4 3. ♘c3 ♞f6 4. f3 exf3 5. ♘xf3. The Ryder Gambit is named after the American chess player Frank James Marshall Ryder, who used it frequently in his games.
However, White can also decide to capture the pawn with the queen, and invite the opponent to the Halosar Trap (named after a chess player Hermann Halosar):
5. ♕xf3 ♛xd4 6. ♗e3 ♛b4 7. O-O-O ♝g4? 8. ♘b5!
As you can see, Black cannot capture the white queen because of the checkmate threat (combined forces of the knight and the rook): 8. … ♝xf3 9. ♘xc7#. At the same time, the white queen attacks the unprotected pawn b7, as the white knight blocks the black queen, so Black will soon suffer from a significant material loss.
It is a risky path, though, because if Black avoids the blunder 7. … Bg4, the material advantage of two extra pawns is usually good enough to ensure the victory. However, the Halosar Trap can be a powerful tactical weapon against average opponents who wouldn’t resist pinning the queen, hoping to win the game quickly.
I checked the database and found 22 games that led to the Halosar Trap. Let me present the most interesting ones.
Black chose a different defense, but there was no rescue for them after the trap sprang.
In this case, Black eventually won, but only because White overlooked an easy path to victory. Check the comments for alternative lines.
Overall, the Ryder Gambit is an exciting and aggressive choice for White in the Blackmar-Diemer Gambit. It offers White the opportunity to quickly develop their pieces and target Black’s weak pawn structure, but it also comes with some risks. Players on both sides must be prepared for a dynamic and tactical game.
If you wish to try out the Blackmar-Diemer Gambit in a safer way, check this video (Teichmann Variation):