I assume a 3/8th high nocking point on my bow string and set my tree up with two black vertical lines on the wall which will replicate where the middle finger of my drawing hand will be on the bow string. The right line is setup for tillering for split finger, the left line is for tillering for three under. As I tiller the bow, I want the trees pull rope to travel straight down whichever line I am using, split or the three under. I also have a pulley mounted on the floor and I slide it to align up with whichever line I am using. When the trees pull rope travels straight down the line, that means the limbs are bending in sync, hence equal limb timing. The pull rope will always drift towards the stronger limb, so I remove wood from the stronger limb and work the bow on the tree till the pull rope travels straight down the line. Equal limb timing makes an awesome quiet, accurate, smooth, fast shooting bow. The bow in the video below has been tillered to 29 inches for a three under shooter and the limbs are timed.