Think of this mark as a reference point. The old method was to measure from tip to tail and mount your bindings with the front of the boot at, in front of, or behind the center of this measurement depending on what type of skiing you were going to use them for. Back then you really only had a choice of what brand and size you were going to buy. There were no twin tips, big mtn, or race boards so this adjustment made all the difference. Nowdays ski boots have a corresponding mark on the sole to line up with the mark on your skiis, but the same rules apply if you mount forward or backwards of this mark. Your skiis will turn faster forward of the line, and they'll be more stable at higher speeds behind the line. Park skiis have their mark forward of the norm so you'll be centered on the ski and have more fore/aft stability, and to make spinning easier. This is an adjustment that can make a dramatic changes to how a ski rides, but only Atomic makes bindings that can move forwards and backwards on the ski without remounting.
Arc 'em or park 'em
