Holmes was only down 1 more time than Ali, though. This was with having 14 more fights and fighting until the age 53. Holmes was hit plenty heavy and stayed up right and the last time he was knocked down was against Mike Tyson. Ali and Holmes were very similar in the chin department, but Ali was overall more elusive than Holmes and therefore was harder to plant and swing at. Ali did indeed take huge shots from Shavers, but it should be noted that it took Shavers 19 rounds to drop Holmes, and it took his self-described hardest punch he ever landed to put him down for 6 seconds.
Well, of course Larry was down, IN ONE ROUND, as many times as Ali was in his entire career, but your point is clear. So, are you prepared to say Larry Holmes had a granite chin?