The Sicilian Defence is a chess opening that begins with these moves:
The Sicilian is the most popular and best-scoring response to White's first move 1.e4. 1.d4 is a statistically more successful opening for white due to the high success rate of the Sicilian defence against 1.e4. New In Chess stated in its 2000 Yearbook that of thegames in its database, White scored 56.1% in 296,200 games beginning 1.d4, but 54.1% in 349,855 games beginning 1.e4, mainly due to the Sicilian, which held White to a 52.3% score in 145,996 games.
17% of all games between grandmasters, and 25% of the games in the Chess Informant database, begin with the Sicilian. Almost one quarter of all games use the Sicilian Defence.