Originally Posted by dzh90
You may be misunderstanding the usage of AoA. Negative AoA means hitting down on the ball. Decreasing AoA (hitting MORE down on the ball) increases backspin.
The reason push draws have more backspin is the geometry of the swing plane. A push draw is hit with in-to-out, decreased AoA, and an open face. Thanks to our better understanding of golf physics, these are not guesses.
Not to be a stickler, but if when you say "increase your angle of attack" almost everyone(even in the d-plane video he uses this term) it means to hit down more on the ball, thus increasing your negative number. True it is a negative number, but let's say you hit 1* down on the ball and someone has to hit down more on it. You are going to try and hit 3* down on the ball. Nobody is going to say try to decrease your angle of attack and have it mean go from hitting 1* down(-1 in trackmans data output) to 3* down (-3 in trackmans data ouput) just because you are going from -1 to -3 which in mathmatical terms is a decrease in the number.
Also you can hit a push draw with out an increased AoA(what you refer to as "decreased AoA". That is not the huge factor on how the ball flies, thus is not really an explanation for why a push draw would have more spin. The open face at impact however will influence it, by launching the ball higher with more spin.