A common error in addressing a pitch shot is to ground the clubhead (setting the club on the ground too far below the bottom of the ball) and to get too bent over at address-to overreach, in effect. When this happens, you tend to resist the law of gravity, killing the roundness and centrifugal force of your swing. Usually you hit the ground first or, as a reaction, pull up and top the ball.
To overcome this, feel that you are standing a little taller than you normally might at address and make sure your arms are fully extended with whatever length grip you have on the club. At this point, the club head should be a quarter of an inch or so off the ground, just barely brushing the grass. The leading edge of the club is still more than half an inch below the center of the ball, so you need not worry about topping the shot and you have reduced the likelihood of striking the ground first. Underreaching in this manner tends to make you help the law of gravity, swinging downward instead of upward, increasing clubhead acceleration and making the swing more accurate.
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