Ruy Lopez that after the common retreat 4.Ba4, Black will have the possibility of breaking a future pin on his by playing ...b5. White must take some care not to fall into the Ruy Lopez, Noah's Ark Trap, in which Black traps White's on the b3-square with a ...a6, ...b5, and ...c4 pawn advance on the . Ercole del Rio, in his 1750 treatise "Sopra il giuoco degli Scacchi, Osservazioni pratiche dell'anonimo Modenese" (On the game of Chess, practical Observations by an anonymous Modenese), was the first author to mention 3...a6. However, the move became popular after it was played by Paul
Sicilian Defence does little for Black's development, unlike moves such as 1...e5, 1...g6, or 1...Nc6, which either develop a minor piece or prepare to do so. In many variations of the Sicilian, Black makes a number of further pawn moves in the opening (for example, ...d6, ...e6, ...a6, and ...b5). Consequently, White often obtains a substantial lead in development and dangerous attacking chances. Meanwhile, advancing a pawn has given Black a there and provides a basis for future operations on that flank. Often, Black's c5-pawn is traded for White's d4-pawn in the early stages of the game, granting Black a central pawn