I used to push out until arm was fully extended and let it drop, worked well most times, but consistency and balance were problems. I tried the drop straight down on second step approach also. It seemed to lower my track, caused a bent arm backswing, slightly late timing and more leverage at the line, resulting in more speed. Seemed very promising, I like the feel at the line and liked having a more powerful shot. This forced me to play deeper in the oil, again inconsistency with release and carry were issues. I dropped maybe 5 pins in average last year using that approach. I am currently pushing the ball slightly forward and down, not extending until I am at the bottom of my backswing. This is a work in progress, feels good so far, too early in the season to say as I have accurracy problems from not having bowled all summer. I will still use the drop on second step when the lanes are dry, And I need to move in and swing the lane with more speed. The slightly late timing helps me to get the ball projected more to the right when I am standing deep. I will let you know how this works out for me.
