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
Ruy Lopez Leko used the Marshall to win an important game against World Champion Vladimir Kramnik. Currently, Armenian Grandmaster Levon Aronian is one of the main advocates for the Marshall Attack. The main lines of the Closed Ruy Lopez continue 6.Re1 b5 7.Bb3 d6 8.c3 0-0. White can now play 9.d3 or 9.d4, but by far the most common move is 9.h3 which prepares d4 while preventing the awkward pin ...Bg4. This can be considered the main line of the opening as a whole and thousands of top-level games have reached this position. White aims to play d4 followed by Nbd2–f1–g3, which