Provide an explanation as to why the welterweight division has always been historically rich in talent relative to the other weight classes ?
I don't think there is a real explanation but I will say that 147 lbs to 160 lbs are the best weight classes to combine power and speed. That combination makes for great fighters.
I think it's because 147 is the perfect balance of size for a collective group of fighters to be big enough to be interesting and fast and powerful. I feel like fighters are a lot slower at 147 above. 147 pounders can match the speed of guys from the lower weight classes and punch as hard as 160 pounders. It might be the most explosive division.
Where speed meets power. Take into account that historically there were only 8 weight classes. Lightweight is still lacking some power. And MW is already lacking some speed. That's only my opinion, though.
Because historically there were more welterweights than any other division. Nowadays superlight has the most fighters, but many of them simply can't compete at light or welter.
The average size male in America is about 5'9 and 190 lbs. Remove obesity from the equation and the average drops. Then make the average person fighting fit and it drops more. Then take into account Welterweights are just 155-160 lbs men who dehydrate and you now have the weightclass in which the largest percent of the population would be in if they were a boxer.
It was always considered that the average weight of most men in america and countries concerned with boxing was 160, and that MW therefore was the marquee division. But WW is the beginning of mixing speed from lower weight classes and power from heavier classes. If the average walking weight as noted above was considered 160 or thereabouts then if training properly those individuals would get down to 147. Thus, there would be a greater pool of fighters to choose from for the WW division, leading to a richly talented division.
Easy answer, as @Reg already touched on. It is a numbers game. There are more athletes that size than any other size, that means more talent, and more contenders.
average man depending on slightly frame deference is about 147 - 160 boxer when trimmed down properly. I like 147 and 154 because they have great speed but also big power. 160/middle weight is when guys (like GGG) carry enough power to put heavyweights to sleep in sparring.
There could be a little bit of proclivity towards the fact that this is the first weight in which men are not being drained off into other sports (be it middleweight like is soccor, heavies in football or basketball..) but I think it is mostly just blind chance.
