I recently saw a video explanation on how the hands work through impact. The instructor was using a training tool to show a thumbs down & up release. Lets dive deeper into some of the illusion of this and understand just what makes the release look as it does.
How firm should the fingers and hands hold the club? We hear all types of beliefs on this subject. I have mentioned it in many articles and videos throughout the years.
Connecting the arms closer to the body for impact is a surefire way to have greater control of the club and enable the big muscles to activate and add power to the release and through swing. The 4:30 path is key. 
One of my PGA Champion Tour pros recently sent me a photo of his divot. Here is why this kind of divot is actually sound and true and a good indication of a proper entry and contact point.
Connection throughout the entire golf swing is not a necessity. There are however certain areas of the swing where connection of the club to the body will aid every player with control and power. Learn more in this video.
Releasing the club can be misunderstood. The arms rotate to impact (or just beyond) and then their job is done. Watch and learn the release and how we envision a wall at impact strike. Then we learn to "move the wall" to the finish