I want to start this post off by clarifying something… your impact and address positions should not be identical. I hear it more than most, but the ‘tip’ of mimicking your address position at impact is not one to follow.
Yes, there are some similarities between these positions, however there are also vast differences.
Despite the differences between these two overlaid images it is clear that my head does not move much at all in relation to these two positions. This shows balance, control, technique and timing. My feet are also stationary, however as I get closer to impact, my right heel will rise off the ground.
To better understand the image let me clarify what each line and circle represent. The blue line and red circle represent my spine angle and hand position respectively at address. Whereas the purple line and yellow circle represent these positions at impact.
The major difference between address and impact position is… movement. Address is a static motion, impact is a quick and powerful explosion of energy.
As you swing down into impact, your left hip begins to turn counter-clockwise quite drastically.
What does this all mean exactly? Well two things, for one, when being fitted for new clubs you must be hitting balls… as many professionals simply fit someone based on your static address position. Two, don’t try and mimic your address position at impact.
Additionally for those of you who have a drastic difference in your hand positions between address and impact, the only way to ensure consistency is through a solid tempo and rhythm. This is because, the further these these positions differ the more difficult it is to make solid contact. This forces your swing to become much more feel-based, rather than mechanically oriented.