When your opponents are 68 and you are at the head with 55, 56, 57, 58 you have to try to position yourself to shoot a 10 if you can’t get two blocks.
At 55 or 56 you need 10 from both ends.
At 57 or 58 you need to shoot the 10 from the head because the opponent will block the 10 from the foot.
Go out on the board with your 3rd shot and your opponent will take you off leaving the 10 open (at 57 you need to be on the 8).
If the opponent stays on the board take your free kitchen shot and if you don’t make it then your partner will have to find a way to win, but otherwise you must shoot a 10.
Don’t worry that you might miss it because if you don’t take it, you will lose.
If you’re at the foot and have 65 or 66 and the opponent has 68 you have to find a way to get two blocks or shoot a 10.
If you get a shot at the 10 you must take it, just do it!