I was amazed at the number of olympic medalists, european champions, US national champions, alter cup champs etc. who competed in the recent F18 world championships. I'm curious what makes the difference in the top 10 or 20 boats. Our sport relies on basic sailing skill in addition to strength, agility and endurance-especially when the wind is up. If the difference at this upper echelon is a combination of luck, sailing knowledge, and having superb agiltiy, strength and endurance-how important is the physical aspect at this level?