Darts Rules Explained: 501, Doubles, Bust And Bogey Numbers

Darts rules look simple from the sofa: throw three, add up, win. Then somebody misses eight darts at double 16, the commentator starts talking about bogey numbers, and the whole thing suddenly needs a translator.

So here are the darts rules explained properly — the scoring, the doubles, the bust rule, the formats you will see on television and the one major that plays by its own set of laws.

Darts rules basics: 501, down to zero, finish on a double

Every standard professional leg starts at 501. Both players throw three darts per turn, subtracting what they score, and the first to reach exactly zero wins the leg. The catch is the finish: the dart that takes you to zero must land in a double — either one of the thin outer-ring beds, or the bullseye, which counts as double 25.

That single condition is what makes darts a sport rather than an arithmetic test. Getting from 501 to 40 is a scoring exercise. Getting from 40 to nothing is a nerve exercise, and it is where matches are actually decided.

What the board is worth

The numbers run 1 to 20 in a deliberately awkward order, with 20 at the top flanked by 1 and 5, so a loose dart is punished rather than forgiven. Each number has two scoring rings: the outer ring doubles it, the inner ring — the treble — triples it.

• Treble 20 — 60, the biggest single-dart score on the board
• Three treble 20s — 180, the maximum for a visit
• Bullseye — 50, and it counts as a double
• Outer bull — 25
• Miss the wire entirely — nothing, and no second chances

A dart must stay in the board to count. If it bounces out or falls, the score is lost, and the player does not get to throw it again.

Going bust, and the numbers you cannot check out

If a player scores more than they need, or leaves themselves on exactly 1, they have “gone bust”. The visit ends, the score reverts to whatever it was at the start of the turn, and the opponent throws. Leaving 1 is fatal because there is no double to finish from there.

This is why professionals set up so carefully. From 98 a pro aims treble 20, double 19 rather than blazing at whatever is nearest, because the wrong 98 leaves an odd number and an extra dart’s work.

The highest possible three-dart checkout is 170 — treble 20, treble 20, bullseye, known as the “big fish”. Above that, and at a handful of scores below it, three darts are not enough. The bogey numbers — 169, 168, 166, 165, 163, 162 and 159 — simply cannot be finished in one visit, however well you throw.

Averages, checkouts and darts’ scoreboard language

Two statistics do most of the talking in televised darts.

The three-dart average is the mean score per three darts thrown across a match. Anything above 100 is a serious performance; the very best nights push beyond 110. It is the cleanest measure of scoring power there is.

Checkout percentage is the share of darts at a double that were converted. A player can average 105 and lose comfortably if they are hitting one double in five, which is exactly why “he cannot miss the treble and cannot hit the double” is the oldest lament in the sport.

The perfect leg — 501 in nine darts — is the sport’s showpiece, and it needs a very specific route. We have broken down exactly how it works in our guide to the nine-dart finish.

Legs, sets and the formats on TV

Matches are built out of legs. In most events, a match is a straight race to a number of legs: best of 11, best of 19, and so on. Deciding legs at the business end of the biggest events are usually played with a two-clear-legs advantage required, so a final does not end on a single fortunate visit.

Some tournaments add another layer: sets. A set is normally the best of five legs, and the match becomes a race to a number of sets. The World Championship at Alexandra Palace uses sets, which is why a match can turn on a single set even when one player has won more legs overall.

Formats also lengthen as an event progresses. The World Matchplay final is a first-to-18-legs marathon — Luke Littler won the 2026 title 18–9 against Gerwyn Price in Blackpool — and stamina becomes as much of a factor as scoring.

The one big exception: double-start at the World Grand Prix

The World Grand Prix, which runs from 28 September to 4 October 2026, plays by a rule found nowhere else on the major circuit. Legs must be started on a double as well as finished on one.

Nothing counts until a double lands. Players can throw six, nine, twelve darts without registering a score, and heavy scorers who live on treble 20 are dragged into a completely different discipline. It is the format most likely to trouble the best player in the world — reigning world champion and world number one Luke Littler — as we set out in our look at the double-start test facing him this autumn.

The setup: the numbers behind the throw

The playing area is standardised, and the measurements matter more than they sound. The bullseye sits 1.73m (5ft 8in) from the floor. The oche — the throwing line — is 2.37m (7ft 9¼in) from the face of the board, measured horizontally. A player may lean over the line but must not step across it.

Darts themselves are capped at 50g in weight and 300mm in length in professional play. Beyond that, setup is personal: barrel weight, grip, flight shape and stem length are chosen the way a golfer chooses clubs.

What the rules do not tell you

Knowing the darts rules gets you as far as understanding the scoreboard. What they do not explain is why a player who has hit double 10 a hundred thousand times in practice cannot find it with a title on the line, or why the noise of a Blackpool or Ally Pally session changes the arithmetic entirely.

That is the actual sport. The rules are the easy part — and once you know them, the rest of darts, from prize money to rankings, opens up. Start with how the PDC Order of Merit works, the list that decides who plays where.

Official rules and tournament formats are published by the PDC, with event coverage via Sky Sports Darts.

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