Easiest weight range to become a "four weight world champion" over?

According to boxrec, Minimum weight has 212 registered boxers, light flyweight 422, 729 for flyweight, and 701 for Super Flyweight. In terms of how many fighters you would have to get through to fight for a title, this is a relatively small amount of boxers you have to get through, so this would be my answer to your question, though no idea if it's the right answer.

 

Logically, the one with the smallest gap - which would be strawweight to super fly (10 pounds) but you still have to factor in the fighter's physical stature. Is it harder for a very small fighter to put on 10 pounds over a career and still be as effective as a young light welterweight (20 years old say) to win a title and move all the way up to middleweight ten years later?

Ruling the lower divisions with a minor belt and defending the title in your home country every time, though, that's got to be the easiest route and I reckon you could do that with impunity in the lowest weight classes.

 

Well you got to look at it in percentages and not actual poundage.

 

Percentage of body weight?

 

I think the lowest ones. Especially since people often naturally put on a few pounds over their career.

 

Depends on who the champs are in each weight class as you move up.

 

This