Complex sentence: He followed with a single of his own to advance Carter to second, and after Schiraldi had Knight down to an 0--2 count he added a single of his own, which enabled Carter to score and putting Mitchell away from scoring himself.
Split into simpler sentences: He followed with a single of his own to advance Carter to second. Knight, batting next, was down to an 0--2 count before hitting another single, which allowed Carter to score and put Mitchell away from scoring himself.