Why do some all-time greats have such ridiculously short primes? And when I say "ridiculously short," I mean primes that end when fighters are in their early 20s. I am often asked this question in regard to Chang, but other prominent recent examples include Tyson & Benitez (you could add Cuevas, though he isn't in the same class as these guys & also a different type of fighter in terms of physical tools, as I will explain). One common theory is the "partying" or "bad training habits" theory. Certainly, the theory applies perfectly to Chang, Tyson & Benitez. Another theory is ring-wear, esp. in terms of having too many big fights at an early age. This applies somewhat to the troika as well, though not as persuasively as the partying excuse. However, another common theme that unites the troika of Chang, Tyson & Benitez (in particular Chang & Tyson) was that they relied so much on their incredible speed & reflexes. But alas, speed & reflexes are the 1st things to go among physical assets that come to play in boxing. So it is my general hypothesis that fighters who rely primarily on (or whose main assets are) speed & reflexes decline at an earlier age than fighters who, for instance, rely on other physical attributes such as size or power (Foreman?) or non-physical attributes such as textbook technical correctness (Finito?). And in the case of Chang & Tyson, that decline was even accelerated by the obvious bad lifestyle they led outside the ring. Comments? Other examples or counter-examples? P.S. This post was prompted by a discussion I had with Val on why I think Pacquiao won't have longevity. Here is an excerpt: "There is 1 trait that Pacquiao has that reminds of me of the prime Chang & Duck has already mentioned this in another thread: his lightning ability to close & widen the gap, which derives mainly from his footspeed. Manny has that ability to close, deliver his shots & then quickly move out of the other's guy's punching range. In fact, the parallels are eery with Chang. What Pacquiao did to Barrera is a carbon copy of what Chang did to Amado Ursua & the slower-handed & slower-footed Mexican fighter in each case had no answers at all. But unfortunately, this asset is all physical & something that leaves you rather early. Pacquiao is already into his late 20s, I believe? How long will he retain it? Chang lost it when he was 22-23, though his is a very special case & Pacquiao obviously takes a better care of his body. But I think my overall point is that when you have a fighter who depends so much on physical advantages (in particular speed), you will likely not have longevity."