Dartboard Number Order: Why 20 Sits Between 5 and 1
The dartboard number order explained for players in England and the UK: the clockwise sequence from 20, why small numbers flank big ones and who devised it.
By CricketTaken EditorialPublished Darts Rules & Scoring22 min read
- Numbered segments
- 20
- Angle of each segment
- 18 degrees
- Total of the numbers
- 210
- Number at the top
- 20
Treble 20 is the bed every professional aims at, and it is flanked by two of the worst numbers on the board. To its left sits the 5; to its right, the 1. A dart that wanders a centimetre or so sideways from the most valuable treble on the board can score 3. That is not an accident of design. It is the design.
Clockwise from the top, the standard dartboard number order runs 20, 1, 18, 4, 13, 6, 10, 15, 2, 17, 3, 19, 7, 16, 8, 11, 14, 9, 12, 5. Small numbers are placed beside large ones all the way round, so that a near miss costs real points. The World Darts Federation and the Darts Regulation Authority both specify this layout, so the board in an English pub, a county match and the PDC's televised stage is the same board, hung with the 20 at the top.
Reading the dartboard number order clockwise from 20
The sequence looks random the first time anyone tries to memorise it. It is not, but the logic is not a simple formula either. What it does, consistently, is put a low number next to a high one, then a high one next to that, then a low one again, alternating as far as twenty numbers allow.
Starting at the top: 20 is followed by 1, then 18, then 4, then 13 and 6. The right-hand side of the board continues with 10, 15, 2 and 17, the bottom with 3 and 19, and the left with 7, 16, 8, 11 and 14, before 9, 12 and 5 return to the 20. Each number covers a wedge of 18 degrees, so twenty of them complete the circle.
Four numbers sit at the points of the compass. The 20 is at the top, 6 on the right, 3 at the bottom and 11 on the left. Players use those four as anchors; the other sixteen fall into the quarters between them.
| Quarter | Numbers clockwise | Total |
|---|---|---|
| Top right, after 20 | 1, 18, 4, 13 | 36 |
| Bottom right, after 6 | 10, 15, 2, 17 | 44 |
| Bottom left, after 3 | 19, 7, 16, 8 | 50 |
| Top left, after 11 | 14, 9, 12, 5 | 40 |
The quarter totals are revealing. The bottom left of the board, between the 3 and the 11, carries the most points of any quarter, and it is no coincidence that the statistical work discussed further down finds that a less accurate thrower should aim towards that side.
Opposite numbers
Every number has another directly across the board from it, ten segments away. These pairings are useful for learning the board because they turn twenty items to remember into ten pairs.
| Number | Directly opposite | Number | Directly opposite |
|---|---|---|---|
| 20 | 3 | 6 | 11 |
| 1 | 19 | 10 | 14 |
| 18 | 7 | 15 | 9 |
| 4 | 16 | 2 | 12 |
| 13 | 8 | 17 | 5 |
The neighbours of the big numbers, and what a sideways miss costs
Look at the board from the oche and the price of a sideways miss is plain. The 20 sits between 5 and 1. The 19 sits between 3 and 7. The 18 sits between 1 and 4. The 17 has 2 and 3 for company. Of the five highest numbers, only the 16, flanked by 7 and 8, has neighbours that are even moderately close to it in value.
At the treble ring the arithmetic is harsher. Treble 20 is 60; drift left and the treble 5 gives 15; drift right and treble 1 gives 3. A thrower who intends to hit 60 three times can, with a little drift on two of the darts, end up with a single 20, a single 5 and a single 1. That 26 is so familiar in English pubs that it has its own name, bed and breakfast, and the board is built to deliver it.
How much room there is
The treble 20 bed is a curved strip only about three centimetres wide from wire to wire, worked out from the WDF dimensions: the treble ring sits about 10 cm from the centre and each segment covers one-twentieth of the circle. A dart that drifts half that distance sideways from the centre of the bed is already in a neighbour. In the single beds further out the segment is wider, but still only a few centimetres at the double ring.
The losses are not symmetrical. A thrower who tends to drift left at treble 20 lands in the 5, a loss of 15 points on a single and 45 in the treble. One who drifts right lands in the 1, losing 19 and 57. Over a match, a player who knows which way they miss can gain a little by shading their aim towards the 5 side.
| Target | Neighbours | Single points lost by a miss into each |
|---|---|---|
| 20 | 1 and 5 | 19 and 15 |
| 19 | 7 and 3 | 12 and 16 |
| 18 | 4 and 1 | 14 and 17 |
| 17 | 3 and 2 | 14 and 15 |
| 16 | 8 and 7 | 8 and 9 |
The rings laid over the numbers and the scoring beds they make
The numbers decide value. The rings decide multiples. A standard board is divided by its wire into twenty wedges and, running across them, a set of concentric rings.
The outermost scoring ring is the double. A dart there scores twice the number of its segment. Halfway in, the treble ring scores three times the number. Between the two, and between the treble ring and the centre, lie the two single beds of each number: the large outer single and the smaller inner single. At the centre are the 25 outer bull and the 50 inner bull.
That makes 82 separate scoring areas on the board: twenty doubles, twenty trebles, forty singles and two bulls. Each number has four, with a single score possible in two of them. Players talk about the "big" single and the "small" single for this reason, and a dart in either scores the same.
How the beds divide the face
The concentric rings and the radial wedges work independently of each other. A segment's number applies all the way from the outer bull to the outside of the double ring; the rings change its value but not its identity. The two single beds are not the same size. The outer single, between the treble ring and the double ring, is the larger, because it lies further from the centre and its curve is longer. The inner single, between the outer bull and the treble ring, is narrower at its inner end and widens as it moves outward. Players often call the outer bed the big 20 or the fat 20, and it is where many missed doubles at the top of the board finish up.
This is why a dart sitting on the double wire between two numbers can be argued over in two ways at once, and why a referee checks the point of the dart rather than the flight.
- Single beds40
- Treble beds20
- Double beds20
- Bulls2
Counted from the standard layout. The outer single and inner single of each number are counted separately because the wire divides them, even though they score the same.
Show the numbers
| Item | Value |
|---|---|
| Single beds | 40 |
| Treble beds | 20 |
| Double beds | 20 |
| Bulls | 2 |
The bull area works differently. The outer bull is a ring around the inner bull, and neither belongs to any number. A dart there scores 25 or 50 regardless of which direction it came from. For finishing purposes the inner bull counts as a double, which matters for checkouts; how that works is explained in our guide to the double out in darts.
Colours and wire: how the layout is painted and separated
The colours are not decoration. They exist so that a player, a marker and a television camera can tell at a glance where a dart has landed.
Single beds alternate dark and light all the way round: black and a cream or off-white. The double and treble beds alternate red and green, and the pairing is fixed: a black single wedge carries red in its double and treble rings, a light single carries green. The 20 is always on a black wedge, so its double and treble are red. The outer bull is green and the inner bull red.
The wire spider
The wire that separates one bed from the next is called the spider. On a bristle board it is a single fabricated structure fixed to the face, with radial wires running from the bull outwards and circular wires forming the rings. Older spiders were held on with staples, which deflected darts that struck them. Modern boards use thinner wire, often shaped in cross-section so that a dart hitting it is pushed into one bed or the other rather than bouncing out. Several manufacturers have competed on that point, since a dart that bounces off the wire scores nothing.
The numbers themselves sit on a separate wire ring around the outside, which on most boards can be lifted off. That allows the board to be rotated so that wear from repeated hits on the treble 20 is spread across the face, with the number ring put back with 20 at the top. Any board hung in competition must show the 20 at the top on a dark wedge, so the board has to be turned by an even number of segments; turn it by one and the 20 lands on a light wedge.
Colours on electronic boards
None of this applies to soft-tip boards in the same way. Electronic boards are moulded plastic with holes rather than a fibre face, and manufacturers use a range of colour schemes on them, often with brighter plastics for the doubles and trebles. The number order is the same; the look is not. A player who learns the board by colour on a soft-tip machine in a bar will find the standard bristle board familiar in layout and different in appearance, which takes a session or two to get used to.
On a bristle board the dark and light alternation has a practical point for the thrower too. Because every second single wedge is black, a player can pick out the 20 segment and the treble 19 bed from the oche without reading the numbers at all, by counting wedges. Most experienced players do this without thinking.
The colours also do quiet work for spectators. A red double on a black wedge, a green treble on a cream one: a camera pointed at the board needs no extra caption for a viewer to see where a dart sits.
The measurements that fix the layout
The number order is only half of the specification. The other half fixes where the rings sit, and it is just as firmly written into the rules. The figures below are those in the WDF specification; the DRA rules for the professional game require the same 451 mm bristle board in the 1 to 20 clock pattern.
| Measurement | Specified size |
|---|---|
| Double and treble ring, inside width | 8 mm |
| Inner bull, inside diameter | 12.7 mm |
| Outer bull, inside diameter | 31.8 mm |
| Centre to outside of double wire | 170 mm |
| Centre to outside of treble wire | 107.4 mm |
| Overall board diameter | 451 mm, with a tolerance either way |
The double and treble rings are the same width, which surprises people who assume the doubles must be easier because they are further out. They are longer, because they sit on a wider circle, but no deeper. The treble ring sits a little under two-thirds of the way out from the centre to the outside of the doubles.
- 170mmCentre to outside of the double wire
- 107.4mmCentre to outside of the treble wire
- 31.8mmOuter bull diameter
- 12.7mmInner bull diameter
Figures from the WDF board specification, in millimetres. Ring widths are measured inside the wire; the board diameter has a permitted tolerance.
Older boards from before the specifications were settled can have wider trebles, thicker wire and staples, and some cheap boards sold for home use have never followed the specification closely. A board used for a league or county match has to meet it. The height and throwing distance that go with the board, which are fixed just as tightly, are covered in our page on dartboard height and distance.
Why treble 20 and not the bull is the scoring target
The bull is in the middle of the board, it is worth 50, and it is round, so it forgives misses in any direction equally. Why doesn't everyone aim at it?
Two reasons. The first is value. Treble 20 is worth 60, ten more than the bull, and three treble 20s make 180 against 150 for three bulls. The second is size. Using the WDF measurements, the treble 20 bed has roughly twice the area of the inner bull. A player aiming at treble 20 who hits it gains more, and hits it more often.
Missing tells a different story, and that is where the number order comes in. A miss around the bull lands in the 25 ring, which still scores 25, or in the inner single of some number, which might be anything from 1 to 20. A miss around treble 20 lands in the 5 or the 1 or in the single 20 above or below. For a top professional the second set of misses still averages higher, because most of them land in the single 20.
Treble 19 as the cover shot
The other job of the number order is to give treble 19 its place. When the treble 20 bed is blocked by darts already in it, a player switches to treble 19, at the bottom left of the board. Its neighbours are 3 and 7: worse than 20's neighbours in one direction, better in the other. Together they come to 10 against the 6 of the 5 and 1.
There is a further reason, which has to do with the doubles. Treble 19 sits in the same segment as double 19, and the bottom of the board leads naturally to the finishing doubles players like: double 16 is only two segments round. A player scoring on 19 who drops below 100 is already looking at the part of the board where many favourite finishes live. A player scoring on 20 has to change line for most finishes, though double 20 itself is directly above.
Treble 18, on the upper right, has a different set of neighbours: 1 and 4. Those cost more on average than 19's neighbours, and the 18 is the third choice for most players, used when both 20 and 19 are crowded or when a finish requires it.
The switch is also about sight. A dart in treble 20 can hide the bed from the next dart; treble 19 sits low on the board, away from the first dart. Players who score on 19 by preference do exist in English darts, and treble 18 has its occasional advocates as well, but the top of the board remains the default.
How well the order punishes a miss
The puzzle is mathematical, and mathematicians have tackled it. The question they usually ask is simple to state. Of all the ways to place the numbers 1 to 20 around a circle, how good is the standard order at punishing a miss?
The simplest measure adds up the difference between each pair of neighbours. On the standard board, working round from 20 to 1 and back to 20 through the 5, the twenty differences come to 198. The largest total any arrangement can reach is 200, so on that measure the standard board is very nearly as punishing as possible. A board numbered 1 to 20 in counting order, by contrast, totals just 38.
Good without being the best
That measure has a weakness. Many arrangements reach 200, and some of them look just as punishing on paper. Mathematicians have since used other measures, for example weighting larger differences more heavily, or looking at runs of high numbers that sit together. On those, the standard board does well without coming top. It contains clusters such as 19 and 16 in the bottom left, with only a 7 between them, that a perfectly "fair" board would avoid, and it leaves the top left with 14, 9, 12 and 5 in a softer run.
The fair judgement is that the order works better than it needed to, and that no one has shown how its designer would have reached it by calculation. Whether it came from careful arithmetic or a good eye, the board punishes inaccuracy. It does not punish it perfectly.
Where a less accurate thrower should aim
A published statistical study, A Statistician Plays Darts, worked out the best place on the board for a thrower to aim depending on how accurate they are. The result follows directly from the number order.
The method is worth understanding, because it explains why the conclusion is sound. The authors treated each throw as landing somewhere in a scatter around the point a player aims at, with the scatter tighter for a better player and wider for a worse one. They estimated a thrower's scatter from the scores of a set of practice throws, then worked out the average score that would result from aiming at every point on the board. Plotted as a map, the result is a heat map of expected score across the face. It shows, for any level of accuracy, which point on the board pays best on average.
For a highly accurate player, the answer is treble 20. Their misses mostly stay in the 20 segment. As the scatter widens, the best aim shifts to treble 19, because its neighbours, 3 and 7, cost less on average than the 5 and 1 around treble 20, and because the bottom left of the board, with 19, 16, 7 and 8, carries a higher total than the top.
For a player whose darts land all over the board, the best target moves again: towards the centre, slightly to the lower left of the bull. A dart that scatters widely from there lands among the bottom-left numbers more often than among the small ones in the top left.
What that means at a pub board
For a league player, the implication is not to stop throwing at treble 20 tomorrow. A player whose darts are clustered tightly enough to hit treble 20 regularly gains from aiming there. But a newer player whose darts land across several segments may score more aiming at treble 19, and a beginner may score more again by aiming at the board's lower centre. Many club players have reached this conclusion on their own. Our guide on how to throw darts covers the throwing side of the question, and the most accurate check is still to keep score of where darts actually land.
Learning the board
Memorising the layout is mostly a matter of chunks. One common method splits the twenty numbers into ten clockwise pairs, starting at the top: 20 and 1, 18 and 4, 13 and 6, 10 and 15, 2 and 17, 3 and 19, 7 and 16, 8 and 11, 14 and 9, 12 and 5. Ten pairs are easier to hold than twenty single numbers.
Another method is by quarter, using the four compass numbers: 20 at the top, 6 to the right, 3 at the bottom and 11 to the left. Each quarter then has four numbers to learn, as the table near the top of this page sets out.
Practice games help. Round the Clock, in which a player must hit every number from 1 to 20 in counting order, sends darts all over the board, which forces the layout into memory. Other practice games use the opposite numbers, for example by switching between a number and the one directly across from it. Several of these are set out in our darts practice games guide.
Finishes that depend on knowing the neighbours
The number order matters most at the finish. A player on 8 who misses double 4 into the single 18 or single 13 is bust; a player on 40 whose dart drops into the 5 next to double 20 is left on 35. Knowing what sits next to a target tells a player which way to miss.
Set-up shots show the same thing. On 41, many players throw at single 9 to leave 32 rather than single 1 to leave 40. The 9 sits on the upper left of the board, next to 14 and 12; a miss to either side leaves 27 or 29, both odd, but a miss into the treble 9 leaves 14, which is double 7. The 1, at the top, sits between the 20 and the 18, and a miss into either of those in the single bed leaves 21 or 23. Neither route is safe in every direction. Both are chosen with the neighbours in view. A full list of the standard routes, which are worked out with these neighbours in mind, is on our darts checkout chart.
Who put the numbers there
The usual answer is Brian Gamlin. He is said to have been a carpenter from Bury, in Lancashire, who devised the order in 1896 to punish inaccuracy and died before he could patent it. The story has been repeated for decades in darts books, pub quizzes and on the back of dartboard packaging.
The darts historian Patrick Chaplin, whose doctoral research on the history of English darts was published as Darts in England 1900-39: A Social History, looked for evidence of Gamlin and found none. The story gives Gamlin a death in 1903, and Chaplin's searches of the death records turned up no such man. His published conclusion is that Gamlin probably never existed.
Chaplin's research points instead to Thomas William Buckle, a wire-worker from Dewsbury in the West Riding of Yorkshire, who is credited with devising the numbering in 1913. A craftsman who made the wire frames that divide a board is a plausible person to have settled where the numbers went. On Chaplin's account Buckle converted a London fives board into a twenty-segment board, which sold locally as the Yorkshire or doubles board, and the treble ring was added later in the south with the numbering left alone. The Buckle account is better supported than the Gamlin one, though it too rests on a thinner record than a historian would like, and Chaplin's own writing elsewhere dates the numbering less precisely, to around the turn of the century.
- 1896, the Gamlin storyA Bury carpenter is said to have devised the order. Research has found no record that he existed.
- 1913, Buckle of DewsburyThomas William Buckle, a wire-worker, is credited by Chaplin's research with the numbering.
- London board spreadsThe trebled London or clock board gains ground over regional patterns as competitions grow beyond single towns.
- Bristle replaces elmBoards made of compressed fibre replace soaked elm, making the layout durable and identical from board to board.
- Written into the rulesThe governing bodies fix the order and dimensions in their specifications, ending local variation for sanctioned play.
A sequence of claims and events as darts historians present them. Dates for the later stages are approximate and the Gamlin claim is unsupported by documentary evidence.
The honest position is that the Gamlin story is unproven and probably wrong, and the Buckle account is the better evidenced. Neither is likely to be settled further now.
The boards that kept another layout
The London board did not start as the only board. Before it won out, England had a whole family of regional designs, many of them with a different number order, without trebles, or both.
The Yorkshire board is the best known. It has the standard numbering but no treble ring. Its game is about doubles and singles, and it survived in parts of Yorkshire long after the London board took over elsewhere.
The Manchester board, often called the log-end, is smaller, made from the end-grain of a log, and has doubles but no trebles. Because it was made of wood, it had to be kept wet when not in use to stop it from drying and splitting. A small number of pubs in and around Manchester kept the log-end board in use for many decades.
The London Fives board is a different design again: fewer and wider segments, numbered only in multiples of five. Its game has its own rules and finishes.
Where they are still thrown at
These boards are rare now, and their survival depends on local leagues and individual pubs. The Yorkshire and Manchester boards in particular have kept small followings in their home areas. Their survival is a reminder that the standard board is a result of history, not a design handed down. How the organised game in England developed around the London board, from pub teams to county darts, is part of the picture in our England sports guides.
How the London clock board became the standard
The London board became the national board through competition. As darts grew from a town game into a national one, competitions with entrants from across England needed a single board, and the London pattern, with its treble ring and its numbering, was the one that won out. Once players had practised on it for the big competitions, it travelled home with them. The process was slower than it sounds: Chaplin records that it was the mid-1970s before the darts press reported the London trebles board recognised as the standard for all major tournaments in the UK.
The material helped. Early boards were made of elm, which had to be soaked to close the holes left by darts and which dried out, cracked and changed shape. Bristle boards made of compressed sisal fibres, introduced in the 1930s, were far more durable and could be manufactured to identical dimensions. A national board needs to be the same board everywhere, and bristle made that possible.
Elm had another problem. A wooden board is a living piece of timber, and two boards cut from different logs never behaved alike; one might hold darts well, another bounce them out. Players who travelled to a match found a board that differed from their own in feel and sometimes in its markings. The fibre board removed most of that. The face was the same from one board to the next, the wire could be fitted to a template, and the number ring could be printed or stamped to the same order every time.
Television finished the job. When darts was broadcast nationally from the 1970s, viewers across Britain saw the same board week after week, with the 20 at the top and the red and green rings, and the regional boards came to look like local curiosities.
The fixed specification
The last step was the rule book. Once national and international governing bodies existed for darts, the board's dimensions and its numbering were written down, so a sanctioned board in England today carries the same order and the same rings as one anywhere else under the same rules.
That is why the question "why is the 20 at the top?" has an answer in rules as well as in history. The 20 is at the top because the rule books require it to be. The rule books require it because the London board put it there. Whoever first arranged the London board's numbers, Buckle or someone else, set the pattern that the whole sport now throws at.