...to rid him of bad habits? Any fighter come to mind?...a beast of a slugger it's hopeless to even try?
There are variables of course like dedication to buy into the system and results breed confidence to learn I suppose a matter of 2-6 months. Think of nfl teams who get a new coach or system that they take in one training camp to change philosophy and win Some are stubborn to stay with the old way and some trainers don't gel with personalities
Silly and shallow question to be honest. It all depends on how fast the fighter learns, how smart the fighter is, how willing he is, how engraved the habits are etc etc. If you take an average fighter, who is average is all of the above variables, then I think 6 months or 3 professional training camps seems reasonable for said fighter to generally lose the habits. The habits cannot be stopped 100% but can be heavily minimised.
Maidana has been with Garcia for over a year and has improved his punch selection ,straightened up his shots and actually got Maidana to use Jabs to set up his power shots. Maidana even slips punches now (well vs Karass Ha) and has improved his head movement slightly. But Defense will always be Maidana's weakness. Garcai won't change the style off Maidana but he has added little things and obviously told him a few tactics to improve him as a fighter.
It's been a while, Joe. My fault. Will miss your phone calls and emails. You were the good uncle I never had. You led a thousand lives. Save me a ringside seat.
Does it ever really work? Usually we see fighters who are known to have a hole in their game narrow the size of the hole, but never really fill it in. Best case scenario, when in the lead they are able to mitigate their bad habits; however, the second they get rocked it all seems to come flooding back.