Quote Originally Posted by The Other Other Santa
"Base" is a mobile, adjusting assertion.

As you move your leg behind their head, you need to adjust your balance point-like infant pupeteer and the rest of the guys sugest. Pulling on the head eliminates the need for shifting your balance but its good to figure out both ways. Try doing the leg switch on a bench and check the changes in balance you get, there's actually alot going on.

think of getting on your Ducati motorcycle from the back: you don't just swing your leg over, you need to move up as you do it...well, I'm full of all kinds of stupid analogies...
SAMBO to the rescue. Damn, I'm just late on all my advice today.