Its a pretty tricky to master sharla...
1.Its hard to be on the offense unless you really know what your doing.
2.If your reflexes arent good...you'll most likely get hit hard with hooks.
3.It involves a lot of angles...and if you dont understand it..you'll continue to throw wide looping punches.

I never knew freddie roach taught it...IMO.Its pointless coming from him b/c his career wasnt good...and he didnt even use it.I personally think that he is overrated as a trainer...sorry to get off of the subject.