the only fight i have seen jake rodriguez in was his knock out loss to pernell whitaker, but as bad as he looked in the fight he must have been much better. he beat charles murray for the ibf title and outpointed the perenial contender ray oliviera in his titleshot. i wonder what jake did well? i remember he was a southpaw.
He basically is the archetypal example of the journeyman who "got good" for a few fights, won a title, then lost the title and slipped back into journeyman status. His win over Murray was a big upset, but even after that he wasn't really that highly regarded as champion (I believe he was the underdog against Tszyu, if I'm not mistaken). Also, I believe Murray beat him in a rematch at some point, if I remember correctly.
I think he made his name by giving Chavez a hard time in sparring, to the point that Chavez allegedly balked at the idea of a fight. Although his victory over Murray was a surprise, Charles had already lost a bit of the shine that he, Mercer and Cole were the future of boxing, according to Roberts... He was the underdog going to the Tszyu fight, but Kostya had been given huge build up and clearly was an almighty classy act.