I play at a place that is at an altitude of 3000 feet above sea level. I have never played at any place at a lower altitude. I have heard that the reduced air density does make a significant difference in the distance a shot (e.g. overhand clear) travels. Given my background in science, I tried to quantify the effects of altitude as well as temperature and humidity in a "scientific" analysis. I had posted this earlier in the equipments forum: http://www.badmintoncentral.com/forums/showthread.php?t=68153 PDF file of analysis report [Ignore the technical part, and take a look at the graphs]. My analysis shows that the same shuttlecock could travel 10% longer in my place than at sea level - nearly 4 feet for an overhand clear shot (Figure 7). This seems very large to me. I would like to hear from anyone who has personally experience with the differences when playing at high altitude. If this makes sense, would it be a good idea to come up with a systematic way to choose shuttlecocks with the right speed given the environment parameters? Regards