411 REFERENCE · Wikibooks
Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bc4/3...Nf6/4. Ng5/4...d5
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Two knights defence C57 Two knights defence → 4. Ng5
4...d5
This is a pawn sacrifice, but it is necessary for Black to defang White's attack on f7.
White must capture the pawn, 5. exd5.
Any other move loses material, for instance retreating the bishop 5. Bb3? Nxe4!.
Theory table
1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5
4
5
Ng5d5
exd5-
References
See also