Choice of the right ski stiffness for the athlete, and the snow and temperature . Stiff skating skis in loose tracks dig into the snow. Norway has data on all the skis in the Norwegian troop, under different conditions, so they generally get the stiffness right. Special powder waxes must also be applied. At this level, all the teams probably didi that, so glide was not substantially different due to glide wax choice.
Special equipment is used to lay in a pattern of fine grooves into the ski sole.
These can vary in width and depth, according to the snow temperature. Norway has developed a sole pattern that works very well under wet conditions. We have seen this several times this season. If the conditions are wet, the Norwegians dominate. This difference gave , for example, Sture Sivertsen better glide against Harri Karvesnemni on the first leg.