McCutcheon Variation, Advance Variation

With 5. e5, White carries out the threat that 4...Bb4 ignored, gaining space and attacking the f6-knight. This position is the main line of the McCutcheon, and Black cannot simply retreat the knight, because the g5-bishop also pins it to the queen on d8. The standard answer, chosen in the vast majority of games, is 5...h6, which hits the bishop and makes White decide at once between retreating it with 6. Bd2, 6. Bh4 or 6. Be3, or exchanging it for the knight with 6. exf6, the variations covered under the parent entry.

The immediate 5...Bxc3+ gives up the bishop pair without first asking the g5-bishop to commit, and White scores noticeably better against it. The rare 5...Ne4 moves the knight off f6 and exposes the d8-queen to the g5-bishop, so it does badly in practice. Engines rate the position as a slight edge for White, but Lichess results are nearly even, with Black slightly ahead overall.