Complex sentence: Semyon became proficient at the game by reading Ken Uston's "Mastering PAC-MAN", this lead him to read other Uston's other titles on blackjack giving him a solid grounding in card counting when he was approached to play with the team.
Split into simpler sentences: Semyon became proficient at the game by reading Ken Uston's "Mastering PAC-MAN". This led him to read Uston's other titles on blackjack, giving him a solid grounding in card counting when he was approached to play with the team.