Because of Black's success in the Open Sicilian - and the huge amount of theory involved in maintaining a mainline Open Sicilian repertoire - many players have turned to White's alternatives on move 2 or 3, the so-called Anti-Sicilians. Although never as popular as the Open Sicilian among grandmasters, and historically considered less critical, these sidelines have always been popular at the club and amateur level, and are a viable option for any player lacking the time or motivation to learn dozens of theoretical lines in each of Black's Open Sicilian options. The most popular Anti-Sicilians all have their adherents among grandmasters and some have even been regularly adopted by World Champions. If you play the Sicilian as Black, especially at club level, you will frequently encounter these attempts to avoid the main lines, and so anyone looking to take up the Sicilian should prepare to spend as much time studying these lines as their favourite Open Sicilian.
Here are some games to demonstrate chances for both sides in the Rossolimo.
Here are some games to demonstrate chances for both sides in the Alapin variation.
Here are some games to demonstrate how White's attack can unfold, and how Black can counter it.