Now, I've spent a few years now writing about the old school belief that the golf swing, for a right-handed player, is controlled by the left hand and arm. It's not, it seems, a popular teaching in many circles today which seem to stress a swing controlled by the large muscles, rather than the hands and arms.
But watching one really fine swinger in particular, Tommy Fleetwood, you can't help but see the importance and the commanding role taken by the left hand and arm in his golf swing. Watching Fleetwood prior to hitting shots, you can see how he is focussing on that left arm. The more you watch the vast majority of good players of today, the more obvious it becomes that the left hand and arm may not be a big factor in some modern teaching, but they still rule in the best swings, just like they did for Bobby Jones, Sam Snead, Jack Nicklaus...
The ideal golf swing, according to Bobby Jones, is a backhanded strike with the left hand. You might even describe it as a two-handed backhand which is now commonplace in tennis. Some modern teachers prefer to teach a swing controlled by the big muscles, rather than the hands and arms. But the reality is that the best players are still using their left hand and arm to control the swing. The left hand and arm leads, and the big muscles just follow right along. That was Sam Snead's view of the world. And no one ever swung the club any better than the Slammer. If you don't believe me, ask Johnny Miller.
If you get a chance, check out Tommy Fleetwood's swing. Check out Ross Fisher, or Richard Sterne, as well. Actually, just try focussing on the left hand and arms of all the pros. They're mostly top hand golfers. It may be old school, but it's always been the most effective way to swing the golf club. It's not the only way. But it's the most effective way.