The conversation will most likely include discussion of how to use a Booster Strap. This is what
@Rod9301 is talking about in the post above. When buckled under the shell in the front of the boot, the Booster binds the lower leg strongly to the rear spine of the boot cuff, eliminating any dysfunctional slop. Slop=lack of control over the forward pressure on the ski.
*note: The Booster is elastic and comes in three levels of strength. It progressively resists allowing the shin to tilt forward inside the liner. The tilt it allows is not usually considered to be "slop."