What's the logic behind a fighter losing in a weight class, then stepping up to higher weight class?

[acannxr]

The Rodrigo fight wasn't in the UFC, and a draw isn't a win, therefor...
...

Except my original post never limited the discussion to just the UFC, and a draw is not a loss, thus that is indeed a "variation in success", especially when that draw was against the #2 welterweight in the world. But if all you want to do is argue over semantics...

 

[Buster C]

There are lots of good answers ITT regarding dehydration and the cut being more difficult with Luke’s age, obvious reasons to move up.

But I haven’t heard any update on Luke moving up since he got KTFO. Maybe Luke knows that DC is planning to retire after fighting Stipe, and he was hoping to go for the LHW belt if he could win at MW.

 

[RichardN7]

It is weird and counterintuitive, but it seems to be a thing.
I think that cutting too much weight is among the shittiest experiences. It leaves the fighters drained mentally and physically... not worth an extra 5 lbs advantage over the opponent... not to mention that being dehydrated makes getting a concussion much easier.
Guys like Cowboy, RDA, Conor at 145, Gastelum, Whittaker... look at how muh better they look a division up, despite not being as big.
It’s easy to sit here and ponder. I’m 175 lbs. If I were to fight, I’d be able to cut down to 155... in theory... I’ve never had to cut weight. I supposed if I did try it, I’d end up preferring to fight at 170. Being small and fresh > being bigger and exhausted.

 

[Foppa21]

It's probably 1/4 I think that may benefit from moving up. But as some alluded to, some people just don't react well to the weight cut or try to cut too much thereby giving up any size advantage they may have. If you don't have the gas tank to fight beyond the first round, you're going to struggle winning fights that make it out of the first.