Over the past several years we have emphasized the importance of keeping your head still during a putting stroke.
Explaining why this is important, and what happens when we lift our head will help us understand the dreaded consequences.
By lifting our head during the stroke, we will break our swing plane (generally causing a pulled-putt and deceleration of the putter head). This becomes most obvious on short putts which are most vulnerable to us trying to control the stroke to get the ball into the hole, instead of trusting ourselves and making a good, in-plane, rhythmic stroke.
Remember – head still, trust your stroke, and stay in plane, especially on short putts.