Marcel Hirscher perfect GS transition

Setting up well above the gate, inside ski (the left foot) tipping and flexing to set up his body.

Here is the critical move, he brings his body together "compact", Hands forward, yet he continues to tip his inside foot and flex his inside leg. He also adds big toe edge  angle, (that's the right foot and ski) Boots and skis always working together to create the same angles. Inside ski and boot tucked and held, well back, under his hips. Too many racers bale-out here and let the inside ski move forward, that's just slow.

Here is where you can be confident, he flexes his inside leg even further and to do so he has to clear space for it to move up, out of the way. This moves the hip more inside the arc. Most racers here, try to step out of the arc, with the up hill ski, hold on for more speed. 

Hirscher begins to flex and relax the outside leg, (right leg) and prepares for transition. 

Flexing the right leg allows the old holding edge,  to dissipate, moving his Cg, center of gravity to the new turn. Now both legs are now evenly flexed. Notice there is no ski lead. Hirscher has minimal ski lead compared to most other contemporary racers. 

Again little or no tip lead. This part of the turn is created because he continued to increase angles by tipping his inside leg and ski. Too many coaches focus on the wrong leg; the outside ski leg, it is less important and doesn't set up the correct body situations.  Of course, once you are in the right part of the arc, adding outside leg tipping and ski angle is correct, but not to set up the arc.