F.Y.I. I am shooting a Mathews Legacy, and aside from sighting in have never really done any kind of tuning, and have been shooting what I thought were decent groups. However I started shooting about 200 arrows every couple of nights to try and improve my odds this year in effort to try and minimize excuses, and found that after shooting that many arrows I still was not as much improved as I thought I should be. I tried grip, no grip, and a few other things, and finally I started to doubt myself or my set up. I took the bow down to the pro shop, and had it reserved the cam timing redone, and took it home and looked down the string from cam to cam and realized that the prongs on my rest were about 1/8 inch out of center according to my eye. I recentered the rest, and started darned near splicing arrows from 30 yds. Long story but a worth while one. What a huge difference practice, and tuning can make. JMO