Portuguese Opening

The Portuguese Opening, 1. e4 e5 2. Bb5, develops the king's bishop to b5 before any knight has moved. It looks like the Ruy Lopez (Spanish Game) with Nf3 left out. There is also no black knight on c6 for the bishop to pressure. Graham Burgess described it as a Ruy Lopez in which White seems to have forgotten the knight move. The point of delaying Nf3 is that the f-pawn stays unblocked, so f2-f4 remains possible. White may also hope that Black chases the bishop with pawn moves that loosen the dark squares or overreach. The price is that e5 is not attacked, so Black can arrange the pieces without being disturbed.

The most frequent reply is 2...c6, which hits the bishop and prepares ...d5. Every retreat has a drawback. 3. Bf1 simply loses two tempi. 3. Bc4 runs into 3...d5 with gain of time. 3. Be2 and 3. Bd3 also let Black set up a broad pawn center. 3. Ba4 keeps the bishop on its diagonal, but 3...b5 4. Bb3 d5 again gives Black the classical center, and engines tend to favor the calmer 3...Nf6. After 3. Ba4 Nf6, White usually continues with 4. Nc3 or 4. Qe2.

The second most common choice, 2...Nf6, develops with an attack on e4 and leaves the question of the bishop for later. Against it, White can open the center at once with the Portuguese Gambit, 3. d4. The move 2...Nc6 invites 3. Nf3, which transposes into the main Ruy Lopez. The less common 2...Bc5 can be met by the Miguel Gambit, 3. b4, which offers the b-pawn to deflect the bishop from the a7–g1 diagonal.

The opening is uncommon and appears mainly as a surprise in casual and online play. In the Lichess database Black wins well over half the games. The engine rates the starting position as roughly balanced, with Nf6, c6 and Bc5 as its preferred replies. Burgess cautioned that the line is less absurd than it first seems and that Black still has to play accurately.