1.e4 e5 2.Nf3 Nf6 Oh no! 3.Nxe5 d6 4.Nf3 Nxe4 5.Nc3 Play 5.d4 to head for the mainlines. 5...Nxc3 6.dxc3 (diagram) 6.bxc3 is okay, but I think it is objectively inferior. The idea is that White is going to play down the half-open d-file and often shove the kingside pawns northward. 6...Be7 Why this? The Bishop is almost assuredly going to develop to the e7 square, while the queenside minor pieces can go to several squares. In particular, Black will clarify the placement of one of the White Bishops, usually the dark-squared Bishop, before deciding whether to develop the Knight to d7 or c6. Now White has two major options: 7.Be3 or 7.Bf4. Which? Let's look at five positions each of higher level games five moves later, after White's 12th. Survey the positions and see if they help the choice based on your preferences.
After 7.Bf4 (five positions five moves later)
Jobava-Motlyev, 11th Karpov Poikovsky Rus 2010
Black is slightly better with the Bishop pair and potential for play down the b-file. White wins the game.
Topalov-Gelfand, Amber Rapid 15th
The game is roughly equal. Black will win the pawn back after the exchanges on d6 by forking the Rook and f-pawn via e4. White wins the game.
Ivanchuk-Kosteniuk, Cap d'Agde CCAS Gp-A Rapid October 2008
The game is roughly equal after Nxe6. White wins the game.
Kramnik-Nielsen, Dortmund 2005
White is slightly better after Be6 due to his space advantage. White wins the game.
Rublevsky-Shirov, Rus ChT 2006
Black is slightly better, but not after 12...hxg5 13.hxg5 and Black has to immediately give back the piece with threats down the h-file abounding. If 13...Be7, then 14.g4 and Black is lost. Black wins the game. On the updside of White's choices after Bf4 is that White is always on the watch for a kingside assault, but as the previous games show, the attack's not a foregone concluion.
After 7.Be3 (five positions five moves later)
Anand-Kramnik, Amber Blindfold14th.
The game is equal. White wins.
Ivanchuk-Wang Yue, Sofia MTel Masters 5th 2009
White is very slightly better. Black wins the game.
Svidler-Kramnik, RUS Ch Superfinal 2005
Again, White is slightly better due to better coordinated pieces and a space advantage. White wins the game.
Jakovenko-Volokitin, Rus-ChT Dagomys 2008
White is slightly better due to better better coordinated pieces and a space advantage. Black wins.
Bolgan-Charbonneau, Canadian op Edmonton 2005.
White is slightly better for the usual reasons and a kingside initiative. White wins.