Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bc4/3...Nf6/4. Ng5/4...d5/5. exd5/5...b5

= Ulvestad Variation =

5 ... b5.
The defining move for the Ulvestad Variation. Black challenges the strong bishop on c4 by offering a pawn.

Theory table
.
 * 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 b5

Ulvestad Variation

Estimated next move likelihood
Bf1 62%, Bxb5 28%, dxc6 6%, Bb3 2%, Qe2 1%