Bishop's Opening: McDonnell Gambit – A Sharp Surprise for White

With 3.b4, you're inviting Black to take on b4 and then immediately chase the bishop with c3. After the engine's best line — Bxb4 c3 Ba5 d4 — you get a big centre with pawns on d4 and e4, your light-squared bishop is active on c4, and Black's dark-squared bishop has been kicked to a5, a somewhat awkward square. You're not worried about the pawn; you care about the two bishops and space. That's the core idea of the McDonnell Gambit: give up the b-pawn to seize the centre and develop quickly. Black often isn't familiar with the best response, and even if they play Bxb4, you have comfortable, active play. Your long-term trumps are piece activity and central control, while Black just has an extra pawn that may become a target.

The most popular move by a huge margin — played in over 14,000 games — is 3...Bxb4. This is the critical test. Your follow-up is 4.c3, attacking the bishop and forcing it to move again. Black's best is 4...Ba5, keeping the bishop on the long diagonal. Then you play 5.d4, planting two pawns in the centre. From here, development plans are flexible: you can bring out your knight to f3, castle kingside, and look to open lines against Black's king. White scores 53.9% from this position, so even in the main line you have the better practical chances. Keep an eye on the a5-bishop — it can become a target if you get a queenside attack rolling with a4 or even Qb3.

Many opponents will shy away from taking the pawn, and the statistics show you benefit when they do. Here are the most common sidesteps and how they fare for White: - 3...Bb6 (4,842 games): Black tucks the bishop away. White scores 47.1% — still playable, but you need to follow up actively to justify the pawn sacrifice. - 3...Bxf2+ (1,406 games): This is a mistake, losing about 1.6 pawns of advantage. Black grabs a pawn but gives you the bishop pair and a huge development lead after Kxf2. Your score is 49.1%, but engine evaluation says you should be much better. - 3...Bd4 (1,392 games): Another mistake (loses ~1.1 pawns). Black blocks the centre with the bishop, but you can attack it immediately with c3 or Nf3, winning time. Your score is 54.5%. - 3...Nf6 (273 games): A blunder worth ~3.9 pawns. Black ignores the gambit to develop. Punish this with ... you'll figure it out in the drill. White scores a crushing 66.3%. - 3...b5 (232 games): Also poor. White scores 70.7%. The lesson: if Black doesn't take on b4 and play accurately, you get a strong advantage.

Three replies from Black are outright errors, according to the engine. Learn to recognise and exploit them: Bxf2+ — Black takes the f2 pawn with check. After Kxf2, you have the bishop pair, Black's king is exposed, and you're down a pawn with massive compensation. The engine says this loses ~1.6 pawns of advantage for Black. In practice, White only scores 49.1% from here, which means many White players don't follow up correctly. Use the drill to sharpen your response. Bd4 — Black places the bishop on d4, blocking your e-pawn and eyeing g1. Attack with c3, forcing the bishop to move again, and you'll gain time. This loses Black ~1.1 pawns. White scores 54.5%. Nf6 — A serious blunder (~3.9 pawns). Black just develops, ignoring the gambit. You should reply with something that exploits the loose f7 square and Black's lack of central control. White scores 66.3% from here — one of the best positions you'll get as White. The drill below will help you learn the punishing follow-ups to all three mistakes.