For me, it varies depending on the amount of spin used to slow down or speed up the ball upon landing. Generally though, I figure a half yard per mph, when its relatively straight on. So, for a 10 mph 12:00 tailwind, I would subtract 5 yards off my club and it should be close. When I am further away (175-225 yrds) and have a strong headwind, like 20 mphs coming straight at me, I will be more likely to add 20 yrds instead of 10 yrds, and take a dot or two of the back spin off so it wont roll back as much. Has been working pretty consistently for me. As far as the 1,2, and 3:00 go, it will vary and be somewhere in between those other #'s, you just need to practice. Just my opinion, good luck.