Complex sentence: During his 16 games stint as manager, his team won three games and lost 13, and he inserted himself into the line-up three times, all in the outfield, which producing one hit, a double, in 12 at bats.
Split into simpler sentences: During his 16 games stint as manager, his team won three games and lost 13. During that time he also inserted himself in outfield for three games, producing one hit, a double, in 12 at bats.