Take a look at his link:

http://www.golfontario.ca/archives/2...shooting.shtml

OK, I don't want to step all over Greg's drill. I am no expert by any stretch so take this with a grain of salt. I think the link both justifies the importance of Greg's drill and maybe adds some caution as far as it's execution. The part about the link that got me to thinking was the amount of "cup" needed in the right hand. In fact, one of the address positions shows a cup in the other direction when one has a weak grip. That looks weird though. For a really strong grip, major "cuppage" is needed. I think the point is no matter how much cup you have it needs to be maintained until impact. But, check your grip. You may be cupping too much or too little which would affect other parts of your swing. I am currently trying to play with a neutral grip because maitaining a lot of cup in the right wrist is difficult.