Here is a look at their top 5 rated fighters: Terence Crawford Saul Alvarez Gennady Golovkin Vasyl Lomachenko Wisaksil Wangek Crawford at #1, based on what? Alvarez holds no titles and arguably lost to Golovkin, yet they have him rated above GGG, in the #2 slot. And Lomachenko at #4?
I don't know the exact formula, but basically what happened is that Pacquiao was rated really highly on Boxrec and was beaten by Horn who then got loads of points for the win, who was then beaten by Crawford who got loads of points.
They don't rate these fighters, it's done automatically by a computer so you get some wacky results. Crawford has beaten a lot of champs which whilst not highly rated by boxing fans perhaps, were still highly ranked divisionally and thus they give Crawford a nice boost. Same with Alvarez, who was #1 p4p for ages, we know that some of his wins are quite controversial but that context is removed when it's done by a computer. All it sees is that Canelo has a W over say a highly rated guy at 154 like Lara, so Canelo's points go up significantly.
I do actually like BoxRec rankings for divisions, that's what I mainly use. There's a few misses but they're obviously completely unbiased and majority of the time it gets them more or less correctly. But their p4p rankings should be completely discarded, p4p as a concept is very subjective anyway and it can't really be done by a computer to a good effect.
Sure the order seems off but hey, with boxrec rankings, I'm pleasantly surprised that it gets it right.