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 Pérez Ponce de León Ruy Pérez Ponce de León Ruy Pérez Ponce de León or Rodrigo Pérez Ponce de León (b. ? - d. 1295) was a Spanish noble of the House of Ponce de León, in the service of the Kingdom of Castile. He was the 15th Grand Master of the Order of Calatrava from 1284 to 1295 under King Sancho IV of Castile and further served as Mayordomo Mayor del Rey from 1293 - 1295, also under Sancho IV. Ruy was the son of the Count of Cabrera, Pedro Ponce de Cabrera and his wife, , one of the illegitimate daughters of