I know this topic has been done to death but....

There's a big deal about Amir Khan getting a top trainer (Freddy Roach). Khan's mob will bring in Roach but then match Khan with an unmotivated "gimme." Khan will destroy the "gimme" in impressive fashion. The impressive performance - which wont be much different from before - will be credited to Roach changing/refining his style, clearly making Khan a far better fighter.

Then Khan moves up in class - gets sparked out.

Did Roach really improve him?

Examples? Thoughts? Feelings?