Chess Opening Theory/1. e4/1...e5/2. Bb5

=Portuguese Opening=

Theory table
The Portuguese Opening is a rare opening starting with the moves 1.e4 e5 2.Bb5. The bishop is ineffective on the b5 square when there is no black knight on c6. It can be easily attacked by Black's c-pawn with 2...c6. Other moves can result in a Ruy Lopez/Spanish Opening (like 2...Nc6 3.Nf3) or other situations, where Black should be fine.

After 2...c6, the bishop can move to f1 (which makes White just waste 2 tempi), c4 (which allows 3...d5 to come with tempo and gives Black a classical center), d3, e2 (which allow a classical center for Black as well) and a4 (allowing 3...b5 4.Bb3 d5 and Black has a classical center, though engines may prefer 3...Nf6).

On move 2, Black can also play Nf6, develop normally, and exploit the bishop on b5 later. The Portuguese Opening is akin to a Ruy Lopez where White does not play Nf3 and is trying to gain pressure on Black's d-pawn. White may be hoping that Black attacks the bishop too much and weakens their dark squares or overextends.

1.e4 e5 2.Bb5