Complex sentence: He is considered by many boxing experts to be the hardest puncher of all time, holding a 91.8% knockout-to-win ratio, and having knocked out 50 opponents in three rounds or less; 24 in the first round.
Split into simpler sentences: He is considered by many boxing experts to be the hardest puncher of all time, holding a 91.8% knockout win ratio. He knocked out 50 opponents in three rounds or less; with 24 in the first round.