While not universal on the PGA/LPGA tours, there are a lot of tour players who employ a noticeable pause at the top of their backswings. This might be similar to music where there's a whole note count of "one" to the top, then a whole note rest or pause ("One"), then a whole note count of "two" for the downswing.
I used to have a pause and I'm working back to that goal. Yesterday I hit 16/18 greens in reg with the pause. Now that's not just about the pause, there's alignment, ball position, and other basics, but the pause seemed to help my body sequence to start the downswing. I felt "calmer". The one thing I did notice was the trail elbow seemed to LOVE the pause. Folks MUST watch Tom's videos about the trail elbow. That said, the pause seems to allow more time for the downswing to unfold.
Tom will attest to the fact that he tries to get students to pause at the top and MANY find it extremely difficult. Even a split second feels like an hour. So are these folks inherently rushing their swings which inhibits downswing sequencing? Or, no matter how hard they try to get into the best positions on the downswing, they are starting too fast and thus the fastest twitch muscle or reflex wins?
So now my swing is "up..one..two". Plus, I ask other guys to tell me if I've truly paused because a pause to me may not be a pause from an external view. They have to say "yep, you paused" or I didn't pause. I can pick any "beats per minute" to do this, but the pause has to be relative to the number of beats per minute. This may sound weird to some, but I've seen golf instructors on the range with metronomes to find a "player's beats per minute", then they use that speed. If could be up.one.two, up...one...two, or up.....one.....two. They even used the metronome for putting and chipping. Tick, tick, tick.
Anyway, I believe the pause is extremely important to master so as to stop rushing the downswing and to allow the body and brain to better sequence the downswing. Plus, the trail elbow really likes having a chance to get in front of the torso which makes all the difference between really good shots with power vs. weak shots with loss of power.
See the fun video about The Inner Game of Golf linked below which will sound familiar to everyone.
Has anyone ever tried to do a constant out loud humming sound during their golf swing ? Some say players can detect their tension spots, or how tense one is during the golf swing when the humming stops or becomes louder or fainter.
It's easy to do without the ball with a club, but try it when actually hitting a ball and see at what point in the swing you might stop humming, which is almost always at the start of the downswing. Try it on the golf course when a shot counts and see if you can even hum to the top, let alone on the downswing.
Also, as for The Inner Game of Golf book, the counting of tick, tick, tick gives the instructional side of the brain something to do during the swing vs. providing a steady stream of oppressive "advice".