So short were some of his killer blows that ringsiders often missed them and questioned what they had seen .
Dempsey modestly said that he needed to knock his opponents down repeatedly to finish them off , but Jack too could be stunningly economical .
So short were some of Dempsey 's killer blows that ringsiders often missed them and questioned what they had seen .
Dempsey modestly said that he needed to knock his opponents down repeatedly to finish them off , but Jack too could be stunningly economical .