Devin gambit

The Devin gambit is an offbeat chess opening that begins with the moves:


 * 1) d4 Nf6
 * 2) c4 e6
 * 3) g4!?

In this gambit, White offers a sacrifice of the g-pawn on g4, where it can be captured by Black's knight. In offering the gambit, White plans to play for central control by placing a pawn on e4.

The opening is tricky and may offer practical chances for White in fast chess. Though the gambit is not often seen in high-level games, though it was used over-the-board by grandmaster Shakhriyar Mamedyarov in a classical game against Andrey Esipenko during the 2022 Tata Steel Masters tournament in Wijk aan Zee. Since then, there has been an increased use of the opening in blitz chess, though there are multiple responses by Black that result in Black obtaining a good position.

History
The opening was played in 1966 in a game at the Lansing Chess Club. Bill Devin, playing with the white pieces, opened with the gambit in a game that resulted in a twenty-one move checkmate. By August 1971, the gambit had become known in Michigan as the Devin Gambit, and a reader of Chess Life & Review wrote to grandmaster and chess columnist Larry Evans asking if the gambit offered a free pawn or if White gained sufficient compensation for the g-pawn offered in the gambit. Evans evaluated the gambit as being unfavorable for White; per Evans, Black accepting the gambit by taking the pawn with the f6 knight would not to open up the position to White's benefit and would not lead to sufficient attacking chances for White.

The line was played by Shakhriyar Mamedyarov in a game against Andrey Esipenko during the 2022 Tata Steel Masters tournament in Wijk aan Zee. At the time, the use of the line was shocking to observers; the move has rarely been seen at high-level play.

Variations and analysis
Black has multiple responses available on move three that provide Black with comfortable play. However, the aggressive opening may offer practical chances for White, particularly in fast chess; following Mamedyarov's 2022 game against Espineko the Devin Gambit has become more frequently played in blitz chess.

3. ...Bb4+
Benjamin Bok, a grandmaster from the Netherlands, argues that 3 ...Bb4+ is the easiest continuation for Black to play. After this reply, White may choose to continue play with 4. Nd2, 4. Nc3, or 4. Bd2.

Against the formermost option, Bok recommends that Black capture the pawn on g4 on move four. Should White continue with their ordinary plan of pushing the e-pawn and play 5. e4, Bok recommends that Black respond with 5...f5, arguing that White lacks compensation for the sacrificed g-pawn. Against other knight move, which places the piece on c3, Bok recommends that Black respond by pushing the d-pawn with 4 ...d5, arguing that the resulting position will yield Black a slight advantage.

Considering 4. Bd2, Bok recommends that Black capture the bishop on d2 by playing 4...Bxb2+. After 5. Qxd2 Nxg4 6. Nf3 f5, Bok argues that Black has achieved equality by the end of move 6. Should White recapture on d2 with the queen's knight on the fifth move instead of with the queen, Bok argues that 5 ...Nxg4 6. e4 f5 allows Black to maintain a material advantage over White without providing any compensation, writing that after 7. exf5 exf5 8. Qe2+ Qe7, White is simply a clean pawn down.

3. ...Nxg4
Evans briefly argued in 1971 that the Devin Gambit is not favorable for White after 3...Nxg4, stating that accepting the gambit granted White insufficient compensation for the sacrificed pawn. Eric Schiller, writing in his 1998 book Unorthodox Chess Openings, analyzes 3...Nxg4 as better for Black with accurate play. John L. Watson and Schiller, writing jointly in their 2015 book Taming Wild Chess Openings, likewise advocate for immediately accepting White's gambit on move 3.

After 3. ...Nxg4, White aims to play for central control by following up with 4. e4. In Unorthodox Chess Openings, Schiller analyzes a line following White's central pawn push beginning with 4. ...Qh4 5. Nh3 Bb4+ 6. Bd2, recommending that Black play 6. ...Bxd2+. After 7. Qxd2 Nf6, Schiller states that Black has a significant advantage. In Taming Wild Chess Openings, Watson and Schiller also advocate that Black reply with 4... Qh4, but provide the White reply of 5. Qe2. After 5. ...Bb4+ 6. Bd2 Nc6 7. Nf3 Bxd2+ 8. Nbxd2 Qh6 White obtains good piece activity, though it was not clear if the activity provided sufficient compensation for the g-pawn.

Watson and Schiller analyze 4. Nf3 as a fourth-move alternative to the above for White, though conclude that after 4. ...d5 Black will obtain a solid position and White will lack compensation for the gambited pawn.

3. ...d5
Watson and Schiller evaluate 3. ...d5 as a good third-move alternative for Black. After White kicks the knight away with 4. g5 Ne4, Watson and Schiller evaluate the position as being good for Black. This response was Esipenko's choice as Black when faced with the opening at Wijk an Zee.

3. ...Bb4+
Wei Yi vs Levon Aronian (FTX Road to Miami, 2022)

3. ...Nxg4
Bill Devin vs Zachs (Lansing, 1966):

3. ...d5
Mamedyarov v Esipenko (Wijk an Zee, 2022):