7.Nxd4 is a patzer's move, not a main line.
White has to play 7.Qb3 (7.0-0 is also playable).
8...Nxe4? gives Black all sorts of trouble after 9.Qh5 (threatening both f7, and Nxc6 when the a5 bishop is hanging).
Are you sure your Houdini is not a faked/ cracked one?
I meant 7.Nxd4 as white, not 8.Nxe4. I'm trying to figure out what makes it a patzer's move.
I meant 7.Nxd4 as white, not 8.Nxe4. I'm trying to figure out what makes it a patzer's move.
White is dropping a pawn as early as move 4, aiming at creating a strong central pawn duo after c3 and d4.
8.Nxd4? just self-destroys this concept without any side benefits, like improving white's development, or creating some tactical threat- rather the contrary, the e4-e5 push has lost much of its punch because there is no knight on f3 for support. Black has a fine game either with the simple 7...Nf6, or the more sophisticated 7...Qf6 followed by ...Nge7.
...dc3 is hardly a big threat for white: by taking another pawn, Black falls further behind in development. While in some occasions Black may afford such a luxury, in general it's very dangerous to do so. 7.Qb3 is considered to be more exact, but after 7.0-0 taking on c3 is just asking for trouble. Examples- plenty of them, here is one where both players are using engines, and Black is unable to solve his developmental problems.
Why isn't this played?
Nxe4 just looks like a free pawn to me, but Houdini gives it -.5. I can't see any advantage black gets out of it, and not taking it allows dxc3.