I understand the rankings, it was the weight I had an issue with. Particularly with the algorithm you speak of. How does it decide where a boxer is placed in terms of weight? As mentioned above, it may appear that boxers are simply classed at the weight they retired at. Doesnt make sense though as Duran is listed at LW rather than SMW. I guess there just a little skewed.
Probably because the fights at 147 were a bit more high profile. Similar to why Henry Armstrong is remembered more as welterweight than as a featherweight, even though 126 was much closer to his best weight.