It’s nearly impossible to train high finishs – instead clever calculation and tactics are in demand.
What is a high finish, anyway? A score of maximum 180 (with Master out) or 170 points (with Double out), in a most possible intelligent way, that promises the highest possible success, brought to exactly zero. With scores like 180, 177, 170, etc., where only one combination is possible, not only the ability is decisive, but also a little bit of luck. With scores, that however let open several ways to check, only one thought should fill the head: Do I still have a chance to finish the match, after the first or second segment missed? Example 122 points: Who still throws to the triple 20 at this score, that is beyond help. A throw in the single 20 and then only a Master out (e.g. 2x triple 17) but no more a Double out is possible. Here would be called for the combination single 18 / triple 18 / Bullseye, as at the first missed try on to the triple 18 you still have a second throw on it, provided, that the first hit at least the single 18. The same with the segments of number 19 at a residual score of 126 or with number 20 at a residual of 130. So: First subtract the highest double from the residual score, set a suitable combination with the previously mentioned information, and then score in reverse order (logical: double finally).