Darts Checkout Routes, Explained
After reading this you will know why 170 is the highest three-dart checkout, why 169 and 159 are impossible, and how to read a checkout route so you leave yourself an easy double when a dart goes astray.
In the standard game of darts you count down from 501 to exactly zero, and the final dart must land in a double. That last rule, called double-out, is what makes finishing hard. You cannot simply hit any number that brings you to zero. You have to arrive at zero by way of a double, which means the score just before your final dart must be an even number between 2 and 40, or a bull (50, scored as double 25).
Take a score of 141 with three darts in hand. One clean route is treble 20, treble 19, double 12: 60 + 57 + 24 = 141. The last dart is double 12, so the leg ends legally. The Darts Checkout Calculator finds routes like this for any score from 2 to 170, then ranks them.
What a checkout actually is
A dartboard has 20 numbered segments plus a bull. Each segment offers a single, a double (outer ring) and a treble (inner ring). The scoring values you can hit with one dart are:
- Singles 1 to 20.
- Doubles 2 to 40 (even numbers only).
- Trebles 3 to 60 (multiples of 3 up to 60).
- Outer bull 25 and inner bull 50 (the inner bull counts as a double 25).
The highest single-dart score is treble 20, worth 60. With three darts the ceiling is 60 + 60 + 60 = 180, but you cannot finish on 180 because the last of those darts is a treble, not a double. The highest score you can finish is 170: treble 20, treble 20, bull, or 60 + 60 + 50 = 170, with the bull acting as the closing double.
A checkout is a sequence of darts that reduces your score to exactly zero, with the last dart landing in a double or the inner bull. Any route that overshoots zero, or lands on 1, or hits zero with a non-double, is a bust: your turn ends and your score reverts to what it was at the start of that turn.
When the calculator helps and when it does not
Use it to learn routes and to check the awkward numbers. Scores under 60 that are already even are trivial once you memorise them. The value is in the 61 to 170 band, where the choice of first dart shapes everything that follows. It is also the fastest way to confirm the bogey numbers, the scores that cannot be finished in three darts at all.
The tool does not know your accuracy. It ranks routes by dart count and by conventional target order, not by your personal hit rate on each double. If you are far more reliable on double 16 than double 20, a route the tool lists second may be better for you. Treat the output as a menu, not a command.
The counting logic behind the routes
Finding checkouts is a small search problem. With d darts left and a score S, you ask whether any single dart value v can be your first throw such that the remaining score S - v is either zero (if v is a double) or finishable with the darts that remain.
Here V is the set of all single-dart values, D is the subset that are doubles or the inner bull, and the large \bigvee means "true if any choice of v works". The recursion bottoms out when d = 1: with one dart you can only finish if S is itself a double from 2 to 40 or a bull (50).
The last-dart constraint is the whole story. A one-dart finish needs S \in \{2, 4, 6, \dots, 40, 50\}. A two-dart finish needs a first dart v such that S - v lands in that same set. That is why the maximum two-dart checkout is 110 (treble 20 then bull) and the maximum three-dart checkout is 170.
A worked example: 141 with three darts
Reproducing the demo
Enter a score of 141 with 3 darts, the tool defaults, and press Calculate. Here is how the search reaches the top route.
- Try the biggest sensible first dart, treble 20 (60). Remaining score:
141 - 60 = 81, with two darts left. - From 81 with two darts, try treble 19 (57). Remaining:
81 - 57 = 24, with one dart left. - 24 is double 12, a legal one-dart finish. The route closes: T20, T19, D12.
- Check the arithmetic:
60 + 57 + 24 = 141. The last dart is a double, so it is valid.
The tool also lists alternatives, such as T20, T15, D18 (60 + 45 + 36 = 141) and T19, T18, D15 (57 + 54 + 30 = 141). All finish in three darts. They differ in which double they leave and how forgiving a missed first dart is.
Reading a route and picking the safe one
Two routes with the same dart count are not equally good. The professional habit is to leave a double you trust, and to leave a number that stays sensible if you miss. Compare finishing 96:
| Route | Sum | If first dart hits single | Left with |
|---|---|---|---|
| T20, D18 | 60 + 36 | S20 = 20 | 76 |
| T20, D18 (aim T20) | 60 + 36 | S20 = 20 | 76 |
The point of the comparison is the fallback. If you aim at treble 20 for the 96 checkout and hit a single 20 instead, you are left on 76, which is still a clean two-dart finish (for example T16 then D14). Routes that leave you on an odd number after a likely miss are worse, because an odd score needs an extra dart to make it even before you can finish.
Prefer routes that leave double 16 or double 20 for the final dart. Both sit directly below an easy fallback: miss double 16 into a single 16 and you are on 16 again for a fresh double 8. Miss double 20 into single 20 and you are on 20 for double 10.
Bogey numbers and the edge of the board
A bogey number is a score you cannot finish in three darts no matter what you throw. With three darts the bogey numbers are 169, 168, 166, 165, 163, 162 and 159. The reason is arithmetic. To finish, your first two darts must reduce the score to a checkable double, at most 40 or a 50 bull. The most you can score with two darts is 120 (two trebles of 20). So your last-dart target must be at least S - 120. For 169 that means the final double must be at least 169 - 120 = 49, but the largest available closing value is 50 (bull) and the only double above 40 is the bull itself. Checking every two-dart combination shows none of them leaves a legal finish for these seven scores.
Common mistakes
The first mistake is forgetting the double-out rule when you plan. A route summing to your score is not a checkout unless the final dart is a double or the inner bull. Treble 20, treble 20, treble 10 sums to 150 but is a bust, because the last dart is a treble.
The second is leaving yourself an odd number with one dart in hand. Odd scores like 17 or 23 cannot be finished with a single dart, because every double is even and the bull is 50. You must waste a dart making the score even first, so a bad route can cost you a full turn.
Do not trust a route just because the numbers add up. Read the last dart. If it is not a double from 2 to 40 or the inner bull, the route is illegal under standard rules and the throw would bust.
The third is ignoring your own accuracy. The tool ranks by dart count and convention. If your best double is double 10, aim to leave 20, not 32, even when both finish in the same number of darts.
Related tools
If you keep score across other sports, these calculators use the same plain-arithmetic approach. For ten-pin, the Bowling Score Calculator handles strikes, spares and the tenth frame. Cricket scorers can use the Cricket Run Rate Calculator for the chase equation and the Net Run Rate Calculator for tournament tables. For team-strength estimates from points scored and allowed, see the Pythagorean Expectation Calculator.
Frequently asked questions
What is the highest darts checkout?
170, thrown as treble 20, treble 20, bull (60 + 60 + 50). The bull counts as double 25, satisfying the double-out rule. No score above 170 can be finished in three darts.
Which scores cannot be checked out in three darts?
Seven bogey numbers: 169, 168, 166, 165, 163, 162 and 159. Each would require a final double larger than the largest legal finish once you subtract the most two darts can score (120).
Why must the last dart be a double?
Standard 501 uses the double-out rule. A leg ends only when the score reaches exactly zero and the closing dart lands in a double (2 to 40) or the inner bull (50). It stops players from grinding down with singles alone and rewards accuracy on the ring.
Is the top route always the best for me?
No. The calculator ranks by fewest darts, then conventional target order. Your own reliability on specific doubles can make a lower-ranked route the smarter choice. Use the list to find a finish that leaves the double you hit most often.
What happens if I overshoot?
You bust. Your turn ends immediately and your score returns to what it was at the start of that turn. Leaving a score below 1, or landing exactly on 1, also busts, since neither can be finished on a double.
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