Darts checkout calculator

What the calculator works out

In 501 or 301 darts you count down from the start and must end exactly on zero with a double. Near the end the question is always the same: what do I throw now? Enter the score you have left and the calculator gives the shortest way to finish with up to three darts, the other routes, and tells you plainly when a number cannot be finished with three darts. A second tab turns points scored and darts thrown into your 3-dart average, the figure used in league tables and on television.

How the table is built

The table is not copied from a chart. The calculator tries every possible dart, the singles 1 to 20, the outer bull (25), the doubles 2 to 40, the bull (50) and the trebles 3 to 60. It keeps every combination of one, two or three darts whose last dart is a double or the bull and whose total equals your score. Of the 169 scores from 2 to 170, 162 can be finished in three darts; the 7 that cannot are 159, 162, 163, 165, 166, 168, 169. One dart can finish the even numbers 2 to 40 and 50, so 50 is the highest one-dart finish; two darts reach as high as 110 (a treble 20 and the bull), and three as high as 170 (two treble 20s and the bull).

Worked example: 141

With 141 left, the calculator returns T20, T19, D12 (treble 20, treble 19, double 12: 60 + 57 + 24). That is the finish that completes a nine-dart leg after two 180s. There are 10 routes in all, and the first one listed uses the preferred double. For 121 the first route is T20, T7, D20 and there are 62 in total. If you leave 169, 168 or any other bogey number the answer is simply that three darts cannot do it; the page shows what a treble 20 would leave instead.

Common mistakes and limits

Treating the outer bull as a double. Only the inner bull, 50, is a double. If you need 25, you cannot hit it to win: the finish for 25 is 9 and double 8, for example, or a single 1 and double 12.

Leaving 1. A double is never worth less than 2, so leaving a score of 1 is a bust and the throw does not count. Plan so that the last remaining number is even.

Assuming a route is the best set-up. The list is complete but not tactical. Players choose between routes by how good a miss is: a first dart that leaves 32 or 40 after a miss is better than one that leaves an odd number. The calculator ranks by fewest darts and the D20, D16 and D8 ladder, which approximates but does not replace a professional's chart.

Limits. The calculator covers straight start and double out, which is the WDF standard (2.01 and 2.02); it does not handle double-in, master out (where a treble also finishes) or other games such as Cricket.

What is the highest checkout in darts?

170, thrown as T20, T20, Bull: treble 20, treble 20 and the bullseye, 60 + 60 + 50. It is the only way to make 170 with three darts. The next highest checkouts are 167 (T20, T19, Bull) and 164 (T20, T18, Bull). Anything above 170 cannot be finished in one visit and has to be scored down first.

Which scores cannot be checked out? What are the bogey numbers?

Below 171, exactly 7 scores cannot be finished with three darts: 159, 162, 163, 165, 166, 168, 169. They are known as bogey numbers (dartcounter.net lists the same seven). Take 169: the last dart must be a double or the bull, and the first two darts score at most 120, so the last dart has to be worth at least 49, which only the bull (50) is. That leaves 119 for the first two darts, and no pair of darts makes 119. The calculator finds these by trying every possible combination of up to three darts, not from a stored list. A score of 1 cannot be checked out at all, and under the bust rule you may never leave it.

Does the bullseye count as a double?

Yes, the inner bull (50) counts as a double 25, so you can finish on it; the outer bull (25) is a single and cannot finish a leg. Under WDF rules the player must land a dart in the double ring or the bull of the number equal to half the remaining score to win the leg (WDF Playing Rules 2.02–2.04). That is why 50 is a one-dart checkout and why the highest checkout ends on the bull.

What happens if I go over, or leave 1?

That is a bust. If a throw scores more points than remain, or exactly the points that remain without finishing on a double, or leaves a score of one, the throw does not count and the score stays as it was before the throw (WDF Playing Rules, 2.05). The darts you threw still count as darts thrown, so a bust drags down your average.

What is a 3-dart average?

The average score per three darts: points scored ÷ darts thrown × 3. If you score 360 points in 6 darts, you are averaging 180. A perfect nine-dart finish from 501 averages 167 per visit, the same as three visits of 167. A dart that misses the double still counts as thrown, so a long finish pulls the average down.

How many darts is the fewest to finish 501?

Nine. The usual version is two visits of 180 (three treble 20s) followed by 141, which you can check out with T20, T19, D12: treble 20, treble 19 and double 12. Another is three visits of 167 (T20, T19 and the bull). Eight darts cannot do it: the last two darts finish at most 110, and the first six score at most 360, so eight darts reach 470 at best, short of 501.

Why does the calculator show a different route from a pro's chart?

Many routes finish the same score. The calculator chooses the fewest darts, avoids extra doubles before the last dart and prefers D20, D16 and D8, since each of these halves down if you miss (D16 to D8 to D4 to D2 to D1). For 100 it gives T20, D20, but there are 281 ways to throw 100 in up to three darts. Professional charts add a set-up preference: they choose the first dart so that a miss still leaves a good number. Both are valid checkouts; the chart is better for strategy, the list here shows what is possible.

Sources: World Darts Federation, Playing and Tournament Rules (20th revised edition, February 28, 2018), clauses 2.01–2.05 and 3.01 (straight start, double finish, the bull counts as 50 and as double 25, the bust rule, start totals such as 501, 701 and 1001); Wikipedia, “Darts” (highest checkout 170 = T20, T20, bull; the nine-dart finish 141 = T20, T19, D12) and “Glossary of darts”; dartcounter.net, “Darts Checkout Guide” (the seven bogey numbers; routes for 160, 140, 121, 100, 80, 64, 40 and 32). Checked by an independent search of every three-dart combination. Related: average calculator, probability calculator and tournament bracket calculator. How we check our calculators.