Darts — a free browser darts game on a real board, with real scoring

You get ten darts and nothing else. Where each one lands is decided by two taps: a marker sweeps left and right across the board, you tap to lock it, then a second marker sweeps down the board and you tap again to throw. The dart sticks where the two lines crossed. It is the same "stop the moving thing at the right moment" skill as a stacking game, except the target is a real dartboard and the reward for precision is spelled out in numbers on the wire.

The board is built to the real proportions — a 170 mm radius out to the outside of the double ring, the treble ring between 99 mm and 107 mm, a 15.9 mm outer bull and a 6.35 mm inner bull — and the twenty numbers run in the standard order, 20 at the top and then 1, 18, 4, 13, 6, 10, 15, 2, 17, 3, 19, 7, 16, 8, 11, 14, 9, 12, 5 going clockwise. Your score comes out of the geometry, not out of a lookup table: the angle picks the segment, the radius picks the ring. Every dart you throw stays on the board, so by the tenth you can see your own grouping. Free, instant, and it plays the same with a thumb as with a mouse.

How to play

• Tap the board (or press Space) to lock the horizontal sweep.
• Tap again to lock the vertical sweep — that releases the dart.
• Ten darts. Your score is the total of all ten.
• Treble ring triples the segment, the outer double ring doubles it, the outer bull is 25 and the inner bull is 50. Anything past the double ring scores nothing.
• The sweeps get faster with every dart — dart 10 crosses the board in well under a second.
• Each throw adds a tiny random wobble, about 2 mm on a real-board scale. It is small on purpose: a good tap is still a good dart.
• A par of 200 is a solid ten darts. 600 would be ten treble 20s, and nobody is getting that.

Why treble 20 is worth 60 and is still the wrong target for most players

Treble 20 is the highest-scoring bed on the board, so it looks like the obvious place to aim. The trouble is that the number order was designed, in the layout traditionally credited to Brian Gamlin in 1896, to punish inaccuracy: every big number is deliberately parked between two small ones. Twenty is flanked by 1 and 5. At the treble ring a segment is only about 32 mm wide, so roughly 16 mm of sideways error — barely more than a dart's own width — turns a treble 20 into a treble 5 or a treble 1, and drops you from 60 points to 15 or 3. The ring itself is only 8 mm deep, which is why most darts thrown at treble 20 aren't trebles at all; they are singles, and the singles either side of 20 are the two worst numbers on the board.

That is what separates face value from expected value. What a target is worth to you is the average of everything you actually hit when aiming at it, weighted by how widely your darts scatter — and that scatter is yours, not the board's. Aim at treble 20 with a tight group and the misses stay in the 20 bed and you are still scoring 20s and 60s. Aim there with a loose group and a large share of your darts land in 1 and 5, and the neighbourhood average collapses. This is why the best place to aim moves as your accuracy changes, which is the single most counter-intuitive thing about the game.

The usual destination for that move is 19, and then the wider 19/16 area in the lower left. Nineteen is flanked by 3 and 7, and sixteen by 7 and 8. Treble 19 pays 57 against treble 20's 60 — three points less in the best case — but the punishment for missing is far gentler: a sideways slip off treble 19 finds treble 7 (21) or treble 3 (9), and the singles around there are 3, 7, 8 and 16 rather than 1 and 5. Take the whole lower-left neighbourhood of 3, 19, 7, 16, 8 and its floor is simply higher than the 1, 20, 5 neighbourhood's. Statisticians who have modelled dart throws as a two-dimensional scatter around an aim point find exactly this: the optimal aim point sits on treble 20 only for genuinely accurate throwers, and slides down and left towards the 19 and 16 region as the spread widens.

The bullseye is the same argument in its purest form. The inner bull is worth 50 — less than a treble 20, less than a treble 19, less even than a treble 17 — while being a circle just 12.7 mm across, the smallest scoring region on the board by a long way. It is the hardest target and it is not the highest-scoring one. It earns its fame from finishing games and from bull-up, not from scoring, and aiming at it to rack up points is a straightforwardly bad trade.

All of that applies here, because in this game your scatter is your timing error rather than your arm. The horizontal tap decides which segment you are in and the vertical tap decides which ring, and since the treble band is thin and the segments are wide, the two taps are not equally forgiving. As the sweeps speed up your effective spread grows dart by dart — so if the top of the board keeps handing you 1s and 5s, the sensible response is not to try harder at 20. It is to aim somewhere the misses cost less.

More games

More things to aim at: sink a putt in Mini Golf, Pool, or test the same stop-it-at-the-right-moment timing in Stack Rush. Or browse all games.