<P> The word "slalom" is from the Morgedal / Seljord dialect of Norwegian slalåm: "sla," meaning slightly inclining hillside, and "låm," meaning track after skis . The inventors of modern skiing classified their trails according to their difficulty . Slalåm was a trail used in Telemark by boys and girls not yet able to try themselves on the more challenging runs . Ufsilåm was a trail with one obstacle (ufse) like a jump, a fence, a difficult turn, a gorge, a cliff (often more than 10 metres (33 ft) high) and more . Uvyrdslåm was a trail with several obstacles . A Norwegian military downhill competition in 1767 included racing downhill among trees "without falling or breaking skis". Sondre Norheim and other skiers from Telemark practiced uvyrdslåm or "disrespectful / reckless downhill" where they raced downhill in difficult and untested terrain (i.e., off piste). The 1866 "ski race" in Oslo was a combined cross-country, jumping and slalom competition . In the slalom participants were allowed use poles for braking and steering, and they were given points for style (appropriate skier posture). During the late 1800s Norwegian skiers participated in all branches (jumping, slalom, and cross-country) often with the same pair of skis . Slalom and variants of slalom were often referred to as hill races . Around 1900 hill races are abandoned in the Oslo championships at Huseby and Holmenkollen . Mathias Zdarsky's development of the Lilienfeld binding helped change hill races into a specialty of the Alps region . </P> <P> The rules for the modern slalom were developed by Arnold Lunn in 1922 for the British National Ski Championships, and adopted for alpine skiing at the 1936 Winter Olympics . Under these rules gates were marked by pairs of flags rather than single ones, were arranged so that the racers had to use a variety of turn lengths to negotiate them, and scoring was on the basis of time alone, rather than on both time and style . </P> <P> A course is constructed by laying out a series of gates, formed by alternating pairs of red and blue poles . The skier must pass between the two poles forming the gate, with the tips of both skis and the skier's feet passing between the poles . A course has 55 to 75 gates for men and 40 to 60 for women . The vertical drop for a men's course is 180 to 220 m (591 to 722 ft) and slightly less for women . The gates are arranged in a variety of configurations to challenge the competitor . </P> <P> Because the offsets are relatively small in slalom, ski racers take a fairly direct line and often knock the poles out of the way as they pass, which is known as blocking . (The main blocking technique in modern slalom is cross-blocking, in which the skier takes such a tight line and angulates so strongly that he or she is able to block the gate with the outside hand .) In modern slalom, a variety of protective equipment is used such as shin pads, hand guards, helmets and face guards . </P>

What do the blue and red flags mean in skiing
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