There are two good ways to take out 61:

25 — D18 = 61 (Best)

T7 — D20 = 61

From 61-80 you can no longer get to a double by hitting a single. In this range we now need to aim at a triple or a single bull on our first dart.

Now it is time to look at the dartboard. Notice how the outer ring of the bullseye is larger than a triple? Anytime you can aim at a bigger target (and still accomplish the same goal) you should do it! That’s why on 61 the best route is going Single Bull (25) to leave yourself D18. If you still aren’t sold on going this route, take a look at my reasoning below:

Bull route 1st dart possible outcomes:

25 — Yay, two darts at D18 now.
50 — Okay, now we have 11. S3 — D4.
Miss the bull entirely into ANY segment — you will be left with a score between 41 and 60. Remember, in that range all you need is a single to get to a double!

T7 route 1st dart possible outcomes:

T7 — Yay, two darts at D20 now.
S7 — Okay, now we have 54. S14 — D20.
Miss into T19 — Happy accident! Now we have D2!
Miss into S19 — Okay, now we have 42. 6/10 wire!
Miss into T16 — Okay, now we have 13. S5 — D4.
Miss into S16 — Okay, now we have 45. S13 — D16.