Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...a6/4. Ba4/4...Nd4

Deferred Bird C70 Morphy defence 4...Nd4!? · Deferred Bird An unusual sideline. This resembles the normal Bird defence with Nd4 on the 3rd move (3...Nd4), but now the knight doesn't attack White's bishop because it isn't on b5 anymore. 5. Nxe5?! is not a free pawn. Black can regain it with 5...Qe7 skewering the knight and pawn, 6. f4 b5 7. Bb3 d6!, and after the knight moves, Black will capture the undefended e4 pawn. However, the most popular move is the tricky 5...Qg5!?. Here are the replies to Qg5: 6. Nf3?? is losing as after 6...Qxg2!, White's knight on f3 and rook on h1 are forked. White has no better choice than to sacrifice the rook with 7. Nxd4 Qxh1+-+, as 7. Rf1? Nxf3+ would be abysmal. 6. Nd3?? is even worse. After 6...Qxg2!, 7. Rf1?? leads to a checkmate after 7...Qxe4+ 8. Qe2 Qxe2#. White has to sacrifice the queen to avoid mate, 7. Qe2 Nxe2-+. 6. Nc4?? is slightly better than Nf3 and Nd3 but is still losing. After 6...Qxg2!, 7. Rf1 Qxe4+ 8. Ne3 blocking the check avoids checkmate, but after 8...Nf3+ 9. Ke2 Qxa4 10. Kxf3-+, despite Black only being up a pawn, White is in an awful position due to the exposed king on f3. 6. Ng4! is testing. After 6...b5 7. d3! (the Bc1 makes a discovered attack on Black's queen) Qg6 8. c3! White is better as they are up a pawn with better development. 5. Nxd4 is White's best move instead. White trades knights, and after 5...exd4 6. O-O! White is better as they have a lead in development and are castled, while Black will have to settle for a worse Bird defence. References See also