[12 piece bucket]

This is the beauty of the Flat Left Wrist is how it maintains the Rhythm. And Rhythm is all in the Left Arm- the Lever System. If you extend the shaft/grip and attached it along the forearm to the elbow - this entire extended line, Flat Left Wrist, the club shaft and clubhead remain INLINE throughout the stroke- even when ACCs 2 & 3 are cocked. That's Rhythm the G.O.L.F. way. It is also a Hinge Motion. Get Rhythm-Go Flat and Stay Flat.

Very nice . . . and note that FLAT is an alignment and NOT a position. Thus your wrist may or may not be physically flat to comply with Flat and ultimately with Rhythm. It's the club and the Left Arm (not the position of the Left Wrist) as Mike so nicely writes.