Interesting list for a Hack Like myself, but i dont understand it, as you say it is for head & tail winds ( only?) how can it be the same extra yardage for both?? I'm confused. For example the chart says 150yd with 20mph wind = 17.5yds, so I read that to mean I need to use a club suitable/capable to reach 167.5yds whether the 20mph wind is head on or from behind... That cant be right can it?