I was reviewing comments after being off the forum for about 12 days while in Tucson, AZ and sometimes it appears we go off on tangents as to what the sail trim controls actually do.To review: there are ONLY 4 things we are adjusting and they are DRAFT POSITION, DRAFT DEPTH, TWIST and ANGLE OF ATTACK.Draft position controls - boom vang, cunnigham, mainsheet, mast bend mainsheet and outhaul. (incresae tension to move DP forward, ease to move it aft) Draft Depth controls - mast bend and outhaul (increase tension to reduce DD and ease to increase depth)Twist controls - boom vang and mainsheet Increase tension to reduce twist and ease to increase twist)Angle of attack controls - mainsheet and traveler (trim in to increase angle and ease out to decrease angle)As you can see some of these controls effect 3 things such as the outhaul. The mainsheet effect 3 things so you have to be careful when you push or pull a control and be sure you know what you are adjusting. The WHY of sail trim is EVERYTHING. One last point - the cunnighams only function is draft postion. It has nothing to do with draft depth.When you consider the jib the fairleads, along with other controls, are used to adjust all 4 items!! That is why an adjustable system is so important (to me anyway) because the adjustments need to be much more precise than with the main.