Here's a pic of Sergio Garcia just before impact. I have drawn a couple of lines on:
Yellow = the angle between his right arm and the clubshaft.
Red = where his hands are in relation to the ball/ground/his body.



As you can see there is almost a 90° angle between the right arm and the clubshaft and the hands are ahead of the ball and practically in front of the left thigh. The hands are leading/driving the club through the shot and the hips rotate out of the way, it all adds up to POWER.

Let's compare that positon to my friend Martin....



As you can see by the lines I have drawn on the angle between the right arm and the clubshaft has been lost, the hands are right above the ball and not in front of it, the impact is in front of the right thigh and not the left thigh.

What is happening here?
Martin's hands do not swing ahead of the club. He stops his hands over his right thigh and then his wrists unhinge, losing that all important lag. It actually makes him jump up out of the shot as he tries to make space to hit the ball without hitting it fat.

What Martin should be looking for is an impact position where his hands are further ahead of the ball... as pictured below...



From this position you can see that the clubhead will be trailing the hands and the angle between the right arm and clubshaft will be maintained. Not only is this a more powerful position leading to more distance, it will also take a fraction of loft off the club at impact making him hit the ball even further still!... and will assist him to stay in a good posture at impact.