Weaker Grip = Active Release
The key to having a good grip is finding one that matches your release of the clubhead. When the hands are positioned in a weaker position on the club, the release through impact must be more active with the hands and arms to square the clubface. The body's rotation slows down earlier in the downswing to allow for the club and arms to fly by. As a result, the right arm extends over the left arm, the shoulders remain squarer to the target line, and the head and chest remain behind the ball. If the body outraces the club to the ball, the weaker grip will produce a short flare into the trees to the right of the fairway, so be careful not to overly weaken your grip.
A weaker grip at address requires a more active release of the hands to square the clubface at impact.
Stronger Grip = Passive Release
A more passive release is necessary when the grip is in a strong position. If the release matched that of the weaker grip, the result would be a nasty hook. Instead, the body must be more aggressive through impact to keep the hands and arms from actively rotating the clubface. As a result, the left arm remains higher than the right after impact, the shoulders and hips continue to rotate and are more open to the target, and the head and chest keep pace with the club, further preventing the hands from taking over. Remember, if you feel comfortable with a stronger grip (hand rotated clockwise on the handle), you must try to keep your body moving through the swing.
The hands and arms must be much more passive with a stronger grip. Otherwise, chronic hooks can become a problem.