A carved turn is a skiing and snowboarding term for the technique of turning by shifting the ski or snowboard onto its edges. When edged, the sidecut geometry causes the ski (in the following, snowboard is implicit and not mentioned) to bend into an arc, and the ski naturally follows this arc shape to produce a turning motion. The carve is efficient in allowing the skier to maintain speed because, unlike the older stem Christie and parallel turns, the skis don't create drag by sliding sideways. Starting a carved turn requires the ski to be rotated onto its edge, which can be accomplished through angulation of the hips and knees applied to both skis, leading them to efficiently carve a naturally parallel turn. Carving turns are generally smoother and longer radius than either stemmed or parallel turns. Carving maintains the skis efficiently turning along the direction of travel as opposed to skidding at an angle across the direction of travel. For a given velocity, carving with shaped skis typically requires less effort than stemming or parallel and offers increased speed and control in even steep descents and highly energetic turns, making it ubiquitous in racing. Prior to the introduction of "shaped skis" in the 1990s, the technique was not simple to learn. Since then, it has become accessible and carving is commonly taught as a form of parallel skiing alongside the classic parallel "brushed" technique. Modern downhill technique is generally a combination of carving and skidding, varying the ratio between the two when rapid control over the turn or speed is required. Pure carving is a useful technique on "groomers" – slopes of moderate steepness with smooth snow – with skis dedicated to this style. Other situations remain almost pure parallel Christie technique, such as competitive mogul skiing, with edged turn initiation aided by the moguls themselves. History Shaped skis, also called parabolic skis, make carved turns possible at low speeds and with short turn radius. Skis had sidecut since they were first carved from wood – typically just 5mm or so on a long ski. But it wasn't until the early 1980s that much deeper cuts were explored. In 1979 Head developed the "Natural Turning Radius" concept and skis with 7.3mm sidecut (~35 m radius). Olin Corp developed a teaching ski with an 8 m radius (31mm sidecut) and the first asymmetric ski, with no up hill cut and,