If you don’t release the club, you end up with what I was battling with last week, a straight push to the right. From your wedges to about the 9 or 8 iron, you can get away with not releasing the club, but from the 7 iron and longer, you clubface won’t close in time.
The issue with me was how I go about consciously closing the club face or releasing the club. So, a great drill I was told was to try and touch your forearms once the club gets passed your waist on the downswing. This causes your left wrist to supinate and your right wrist to pronate. It also promotes the “back handing” of the left hand to the target at impact. This roll continues past impact.
Another drill is to keep your feet close together and swing from 3 o’clock to 9 o’clock. Without thinking about it, you are actually releasing the club! You can actually see your right wrist starting to come over the left wrist before impact, square the club face at impact and continue to roll over your left wrist past impact.
I’m no expert, but these drills help me understand the concept of releasing the club.