If the left wrist got to vertical too early, wouldn't #3 have released prior to #2? Not good...
Kevin
I don't think it actually works like that . . . you got "released" and "releasING". Obviously the sequence is 4-1-2-3 . . . HOWEVER it doesn't mean that each accumulator is released fully before the next one fires . . . 4 starts to go first in the chain but she don't go all the way to in-line at impact or the primary lever assembly wouldn't lean on the ball.
But I think the point Mr. Kelley was trying to make was/is . . . the wrist conditions are Flat Level Vertical at Impact right . . . so once the wrist reaches it's vertical condition . . then #2 is pretty much uncocking vertical at that point . . . if you never got your wrist back to vertical you be uncocking the hosel at the ball. {Now that deal make work a bit different with a 10-2-D grip because essentially Turned is vertical there.) Try the motion really slow from say club at say toe up in the release . . . swivel the wrist into its vertical alignment from there . . the plane of the uncocking is dang close to the vertical hammering motion (as #4 continues to release, pivot goes forward, and #3 continues to go).