The seven scores you cannot finish in three darts
In standard double-out darts, 169, 168, 166, 165, 163, 162 and 159 cannot be finished in one three-dart visit. They are often called bogey numbers. This list concerns scores below the maximum checkout of 170: any score above 170 is also out of reach in three darts. The rule applies equally to double-out 501 and 301.
Leaving one of these scores is not a bust. Your points still count and you continue on your next turn; you simply cannot win with the next three darts. Do not confuse a bogey number with leaving one point. A remainder of one is a bust in double-out, because there is no double worth one.
Why 170 works and 169 does not
The highest single-dart score is T20, worth 60. The highest finishing dart is the inner bull, worth 50 and treated as D25. That gives 60 + 60 + 50 = 170. For 169, finishing on bull would require 119 from the first two darts. Two trebles sum to a multiple of three, and using a double or single instead cannot reach 119. Finishing on D20 or below would require at least 129 from two darts, which is more than the maximum 120.
A lower remainder is therefore not always a better remainder. That matters most when your opponent can finish on the next visit. You want to leave yourself a chance if they miss. It does not mean that a difficult 170 is a realistic target every time, or that you should abandon a comfortable scoring target long before a finish is relevant.
Three last-dart decisions to remember
These examples assume you have one dart left in the current visit. S means single and T means treble. Check the remainder before throwing: a small change of target can keep a finish available for your next turn. Neither the single nor the treble on the suggested number leaves a three-dart bogey in these examples.
| Before the dart | S20 leaves | Alternative |
|---|---|---|
| 186 | 166 | S19 → 167; T19 → 129 |
| 182 | 162 | S18 → 164; T18 → 128 |
| 188 | 168 | S18 → 170; T18 → 134 |
Count the darts still in your hand
A score can be a valid three-dart finish without being a two-dart finish. For example, 100 can go T20, D20 in two darts, while 99 needs three. The maximum with two darts is 110 through T20, bull; with one dart it is 50 through bull. These limits do not make every smaller number finishable in that many darts.
Use the checkout calculator to check both the remainder and the dart count. If you have 99 and only two darts, plan what you want to leave rather than attempting an impossible finish. On a small remainder, the ten starter checkouts give you simpler decisions to practise first.
A five-minute setup drill
Write 186, 182 and 188 on a card. For each score, say which number you would aim at with one dart left, then name the remainder after a single and a treble. Check the arithmetic before you throw. Repeat with the scores in a different order until you can make the decision without reading your previous answer.
Next, play an ordinary 501 leg and pause briefly before the final dart of each visit near a checkout. Ask what a single on your chosen target leaves. Keep the card beside the scorer; this is a manual decision drill, not a built-in app feature. Learn a few useful cases well before trying to memorise every possible setup.