[12 piece bucket]

Is it waist bend, or knee bend? I agree that increasing waistbend is better than standing up through the ball. But my twisted logic is that being too bent over tends to promote coming out of your spine angle, especially if you are on a flatter plane.

Maybe . . . but there's probably some range of motion stuff in that equation as well. Optimal "out of line" angles that go to in line more pivot train . . . . that being said I'm sure there are economies of scale there too.