Why Are some Weight Classes Deep?

Why are some weight classes so much deeper than others? I swear, some classes I struggle just ot remember 2 guys at that weight, and others I can name 15 off the top of my head. Perfect example is Jr Welterweight at 140. That is one of the deepest weight classes around.

So my question is, is it a situation where alot of guys are just born a certain size, or is it a matter of guys changing their weight to chase big name guys, or what?

It's a combination of $ and biology.

Well maybe to put it another way, why do guys stick to the weight class they're in, when it would be easier to go up or down 5 lbs and win a title? They can be #9 at 140, or #1 at 145, so they stay at 140? It just doesn't make much sense to me

I guess coz for two reasons:

1. The more stacked the division, the richer it is.
2. Boxers generally don't like to concede and admit that other fighters have more ability than them.

I doubt there are 9 guys at 140 that would beat Mayorga, Spinks and/or Forrest

it was just an example. U4EA, it just seems weird that some guys will move up 20 lbs so that they can be mediocre, instead of staying where they were and being the best. Seen lots of guys fighting at 150 that started their careers at 130

Its hard to stay light when you grow up.

Micky Ward was a Jr Welterweight for 20 years

He's the exception. Duran started his career as a bantam or something like that, and finished a SMW.

It'll all change in another 2 yrs, then again ina another 2 etc etc...its all law of averages...

just like in bball, the west is so dominant and people are paniciking "What do we do about the East!!!!"....leave it, eventually it will even out...same as in boxing...

Duran mover up cause he was too lazy to maintain his weight. That's why most people move up, actually