Just how important is a centered string, and what are some techniques to assure the string is centered when manually cocking?

it is very important to get the string cocked straight,, just a wee bit off will cause your bow to shoot off to one side or the other..

if you cock you crossbow by hand mark the string when it is at rest on both side of the riser/rail and then chec to make sure the marks are still at the same spot on the edges of the rail as they were when the string was at rest..

Centering the string is crucial to accuracy. You can mark the string on either side of the rail while bow is uncocked w/ "sharpie" or some use white out. Then check when cocked to make sure marks are even on or near rail. Most use rope cockers which do a good job of centering the string while cutting the effort in half.

Just being off a little will through your arrow way off! It is very important! Mark your string as said above and then just check after cocked to make sure it is centered.

Good information, Thanks. Off to mark my string.