[BerntR]

The left wrist controls the clubface, right? If the FLW is at the right place at impact - does it really matter that much what happens in the backstroke - it's the downstroke and especially how the left wrist works at impact that counts? Or?

The back stroke is very important. Start to study the back stroke of your playing partners. You should soon be able to spot something being off in the early part of their back stroke when they hit poor shots.

All the pros you see on TV have a "perfect" back stroke by comparison so you have to study "real" golfers to appreciate this.