Complex sentence: During those six seasons Garcia compiled a record of 104 wins against 57 losses, posting a pair of 20-win campaigns and leading the American League in earned run average (ERA) and shutouts twice each.
Split into simpler sentences: During those six seasons Garcia compiled a record of 104 wins against 57 losses. He also posted a pair of 20-win seasons and led the American League in earned run average (ERA) and shutouts twice each.