How to keep score in darts (501)

Darts scoring at a glance

Rule	How it works in 501
Start	Both players start each leg on 501. Every dart counts from the first visit (straight in). 301 is the same game from a lower start.
Turn	A visit of 3 darts. Players take one visit each, in turn.
Scoring	Add up the visit and take it off your own score.
Winning a leg	Reach exactly 0, with the last dart in a double or the bullseye.
Bust	Score more than you need, leave 1, or reach 0 without a double. The visit scores nothing.
Match	Best of a number of legs, or of sets made of legs.

How is a dartboard scored?

A dartboard has 20 numbered segments. Clockwise from the top they run 20, 1, 18, 4, 13, 6, 10, 15, 2, 17, 3, 19, 7, 16, 8, 11, 14, 9, 12, 5. Where a dart lands inside a segment decides what it is worth:

Where the dart lands	Score	Example
Single (the wide beds)	The number	Single 19 scores 19
Double (the thin outer ring)	2 times the number	Double 16 (D16) scores 32
Treble (the thin inner ring)	3 times the number	Treble 20 (T20) scores 60
Outer bull (the ring around the centre)	25	Not a double
Bullseye (the inner bull)	50	Counts as a double (double 25) for finishing
Outside the double ring	0	A miss still uses up the dart

The best single dart is treble 20, worth 60, so the most one visit can score is 180: three treble 20s, called a maximum. Not every total below that is possible. No three darts add up to 163, 166, 169, 172, 173, 175, 176, 178, 179, so if one of those is called, the score is wrong.

How does counting down from 501 work?

You throw three darts, add them up and take the total off your score. Then your opponent does the same with theirs. The two scores never touch: nothing you throw changes your opponent's total.

Say your first visit is T20, 20 and 5. That is 60 + 20 + 5 = 85, so 501 becomes 416. A visit of 100 next time leaves 316. On a chalkboard or scoresheet, write each visit's total with the score left beside it, so a mistake is easy to find later.

Keep going until you are on 170 or less. From there you may be on a finish: the score can be checked out in one visit, and the leg can end.

What is a bust in darts?

A visit is a bust if you:

• score more than you have left,
• leave exactly 1, or
• reach 0 with a dart that is not a double or the bullseye.

After a bust your score goes back to what it was before the visit, and the turn passes. The whole visit counts for nothing, including darts that scored before the one that bust, and darts thrown after a bust do not count.

Leaving 1 is a bust because no double is worth 1, so a score of 1 could never be finished. It usually happens like this: on 21 you aim at the single 5 to leave 16 for double 8, and the dart drifts into the 20 next to it. That would leave 1, so it is a bust, and you are back on 21 next visit.

What does double out mean?

Double out is the finishing rule in 501: the dart that takes you to exactly 0 must land in the double ring or the bullseye. On 40 you aim at double 20, on 32 at double 16, and on 50 you can take the bullseye.

Every double is an even number, so an odd score cannot be finished with one dart. Throw a single first to leave a double: on 41, a single 9 leaves 32 for double 16. With three darts in a visit, you often get more than one go at the double.

Double out sets three limits worth knowing:

• The lowest checkout is 2 (double 1).
• The highest checkout is 170: T20, T20 and the bullseye.
• Seven scores below that cannot be finished in one visit: 159, 162, 163, 165, 166, 168, 169. These are the bogey numbers.

Some casual games drop the double and let any dart finish. That is straight out, and double out vs straight out compares the two.

A 501 leg, visit by visit

Here is a full leg of 501, double out, between Alex and Sam, with Alex throwing first. The fourth column shows both scores after each visit. Watch visit 9: Alex is on 21 and busts by leaving 1.

Visit	Player	Scored	Left (Alex · Sam)	What happened
1	Alex	100	401 · 501
2	Sam	81	401 · 420
3	Alex	140	261 · 420
4	Sam	100	261 · 320
5	Alex	180	81 · 320	On a finish: T15 · D18. A maximum: three treble 20s
6	Sam	60	81 · 260
7	Alex	60	21 · 260	On a finish: 5 · D8. Alex misses the finish on 81 and leaves 21
8	Sam	140	21 · 120	On a finish: T20 · 20 · D20
9	Alex	20 (bust)	21 · 120	Bust: the score goes back to what it was. Aiming at the single 5, the first dart lands in the 20 next to it and would leave 1. Alex stays on 21
10	Sam	80	21 · 40	On a finish: D20. T20 and 20 go in, but the third dart misses double 20
11	Alex	21	0 · 40	Checkout: leg won. Single 5, then double 8

Scored visit by visit by the same bust and finish rules the app uses.

Alex needed six visits to win the leg, and the bust counts as one of them. Counted per visit, as the app counts it, that is 501 points in 6 visits: a 3-dart average of 83.5 for the leg. Sam was left on 40, needing double 20.

Which checkouts should you learn first?

You do not have to learn every checkout at once. A few patterns cover most of them: an even score up to 40 is its own double, a single and a double finish most scores up to 60, and a treble and a double finish most scores up to 100. These examples show each pattern:

Left	Finish the app suggests	Darts	Note
2	D1	1	The lowest checkout
32	D16	1	Miss into the single 16 and 16, 8, 4 and 2 are all still doubles
40	D20	1	Double 20, called tops
41	9 · D16	2	An odd score: a single first, then a double
50	18 · D16	2	The bullseye also finishes it with one dart
61	11 · Bull	2	A single, then the bullseye
81	T15 · D18	2	A treble, then a double
99	T20 · 7 · D16	3	The lowest score that needs three darts
100	T20 · D20	2	The highest finish with a treble and a double in the ring
110	T20 · Bull	2	The highest two-dart finish
121	T20 · 11 · Bull	3	Two setup darts, then the bullseye
170	T20 · T20 · Bull	3	The highest checkout

Routes computed by the same checkout rules the app uses.

The checkout chart gives the finish for every score from 2 to 170 that can be checked out, with other routes and what to throw when a dart misses.

How do legs and sets work?

One countdown from 501 to 0 is a leg. A match is won in legs or in sets:

Format	How the match is won	Examples
Legs	Win more than half the legs	Best of 5 legs is first to 3; best of 11 legs is first to 6
Sets	Win more than half the sets. Each set is a race of legs, normally best of 5 legs (first to 3)	Best of 5 sets is first to 3 sets

Throwing first is an advantage, so it is shared out. Before the match each player throws one dart at the bull, and the nearer throws first; this is the bull-up. After that the first throw alternates every leg. In a sets match the first throw of each set alternates too, so a player can start the last leg of one set and the first leg of the next. Winning a leg your opponent threw first in is a break of throw; winning the leg you started is holding throw.

A deciding leg is normally just one more leg. One exception is the PDC World Championship: in the final set of a match, a player has to win by two clear legs, with a sudden-death leg at 5-5.