I get asked this quite frequently in regards to tuning so I figured I would share a short reasoning behind it.
Most hybrid cams will require the top cam to hit slightly ahead. This will be more apparent when you get into really fine tuning a setup with creep tuning. The reason behind this is do to the the extra flex on the Control cable as your top cam hits at the same time as the bottom. When you synch so top cam is ahead you are pre loading the control cable and then when the bottom cam hits the buss cable your top cam is more firm with pressure on the control cable. This will give you less variance when pulling through the shot and tighter groups as a whole. With that said, it is a small window and never nothing drastic as far as cam advancement.
When this is done it is not a matter of adjusting for it and calling it good. Your rest will need to be adjusted accordingly to work together to get the best possible vertical nock travel.
Now if you have a drawboard you can take your bow to full draw and lock it in just before the cams hit your cables. Then apply pressure with your finger where the cams will hit the cables on top and bootom. You will notice how much extra flex is in the control cable in comparison to the bottom cam hitting the buss cable.
Hope this helps shed some light as to why it works and the reasons behind it.
Most hybrid cams will require the top cam to hit slightly ahead. This will be more apparent when you get into really fine tuning a setup with creep tuning. The reason behind this is do to the the extra flex on the Control cable as your top cam hits at the same time as the bottom. When you synch so top cam is ahead you are pre loading the control cable and then when the bottom cam hits the buss cable your top cam is more firm with pressure on the control cable. This will give you less variance when pulling through the shot and tighter groups as a whole. With that said, it is a small window and never nothing drastic as far as cam advancement.
When this is done it is not a matter of adjusting for it and calling it good. Your rest will need to be adjusted accordingly to work together to get the best possible vertical nock travel.
Now if you have a drawboard you can take your bow to full draw and lock it in just before the cams hit your cables. Then apply pressure with your finger where the cams will hit the cables on top and bootom. You will notice how much extra flex is in the control cable in comparison to the bottom cam hitting the buss cable.
Hope this helps shed some light as to why it works and the reasons behind it.