Front side

[Bobby Shirer]

Clemenslee1

I have giving this some thought as well. I plan on testing.

I think you land on a flexed leg and then the quad rapidly contracts. There is some relaxed to contraction.

The problem with thinking about the front leg is the same as pulling to the ball with the upper body. If you think about it, chances are the weight will get onto the front leg. Instead of hitting against the front leg.

Try this for feel so you dont' get on the front leg.... Push so hard against the front leg that you actually move rearward upon completion of the swing. Like Barry...
The pics are from this video. Interestingly, watch at the 2:28 mark and see how un-important follow through is.

 

[Bobby Shirer]

See whatever stride used prior to launch position as part of the timing mechanism.

Edit: See launch position needed to be attained just prior to heel plant.

For me Sierra Romero is very near her launch position in the picture.

View attachment 18744

....because everything prior to heel plant is timing, loading, and setting up force direction of the swing. If the bat moves forward prior to that, power bleeds away.
I believe the bat wrapping behind the head at this point (prior to the swing) really winds the spring tightly for a super explosive launch.