This has been around for a while, but in the last few years, has taken off in popularity due to people discovering how accurate it is for selecting bows. Have you ever had that bow that you could just shoot scary accurate with, and do it effortlessly? There may have been a bit more to it than just the bow being may have been that the formula fit you in what they are calling the "sweet spot". It's more than just picking a long A-A bow and large brace factor in your draw length. The math is to take your draw length minus the bow's brace height...then divide that number by the bow's a-a length. This will give you a number...and apparently, the "sweet spot" has been determined to be in the .535 to .635 zone.

I thought this was kind of silly at first...until I started playing with it, and was quite shocked at either how accurate the formula is...or how coincidental it is. I've owned a lot of bows...some that were target specific with large brace heights and A-As...and couldn't shoot them worth a hoot. Those bows aren't even close to the sweet that's neat. I have a couple of bows that I've shot that are just awesome to me...I shoot them really well...both land in the sweet spot of the chart.

Here's a link to it. It does the math for you...all you gotta do is put your draw length in, and start clicking on the list of bow manufacturers, and it will show you the bows that fall into the "sweet spot" range for your particular draw length.