Darts · DartDrill
How do you play Bob's 27 in darts, and what is a good score?
Bob's 27 is a doubles practice game. You start on 27 and throw three darts at each double from D1 to D20, then the bull. Every hit adds that double's value; a round with no hits subtracts it once. If your score reaches zero the game is over. A perfect game scores 1,437.
Where Bob's 27 comes from
The game is credited to Bob Anderson by darts coaching sites including DartHelp, Decent Darts and GoDartsPro. Anderson, nicknamed the Limestone Cowboy, is from Winchester and won the 1988 World Professional Championship, beating John Lowe 6–4 in sets in the final, according to his Wikipedia biography. DartHelp says he invented the game for the sole purpose of practising doubles.
That purpose explains its shape. In 501 every leg ends on a double, so a game that makes you throw at every double on the board, in order, with a score that punishes long runs of misses, is about as close to finishing pressure as solo practice gets. DartHelp calls it a great solo game that also works with friends.
The rules, round by round
You start on 27 points. Round one is double 1, round two is double 2, and so on up to double 20, with the bull as the last target, which makes 21 rounds in all. Each round is three darts at that round's target, and only the target counts: singles, trebles and other doubles score nothing.
Every dart that lands in the target double adds that double's value. GoDartsPro's example is double 6: hit it once and you add 12, hit it three times and you add 36. If all three darts miss, you subtract the double's value once, so missing double 6 completely costs 12. The bull is worth 50 a hit, and Decent Darts warns that missing it costs 50, which catches many good players at the very end.
The game ends early if you run out of points. DartHelp puts it as your score reaching zero; Decent Darts says falling below zero. Apps vary too. Gran Darts' version plays all 21 rounds and the highest final score wins, with an optional Hard Mode that eliminates a player whose score drops to zero, a Reverse Mode that comes back down from the bull to double 1, and an Even Mode that uses only the even doubles.
Keeping score, and the odd-number check
A short example shows the arithmetic. Start on 27. One dart in double 1 adds 2, making 29. Missing double 2 with all three costs 4, leaving 25. Two darts in double 3 add 12, making 37. DartHelp's own example is a perfect first round: three double 1s add 6 and take you to 33.
DartHelp also gives a quick sanity check: your score should always be odd, and if it is even you have made a mistake. The reason is simple. You start on 27, an odd number, and every change in the game is an even number, because every double and the bull are worth an even number of points.
That check settles the zero question too. Since the score is always odd, it can never land exactly on zero; it goes from a positive odd number straight to a negative one. In practice, reaching zero and falling below zero end the game at the same moment.
The 1,437 maximum and what a good score looks like
GoDartsPro, DartHelp and Decent Darts all give 1,437 as the perfect score, and the arithmetic is easy to check. Doubles 1 to 20 are worth 2, 4, 6 and so on up to 40, which adds up to 420. Three hits on each makes 1,260. Three bulls add 150, and the starting 27 brings the total to 1,437.
The low doubles are the dangerous part. They are worth very little, and 27 is a thin cushion: miss doubles 1 to 4 completely and you have lost 2, 4, 6 and 8, leaving 7. One more blank round at double 5 costs 10 and ends the game before you have reached the side of the board you practise most.
For a good score, Decent Darts offers a rough guide rather than a table. The average player, it says, will be happy simply not to fall below zero and to get as far round the board as possible. Players who practise regularly and are of a good standard should find about 400 and above within reach if they hit most of the doubles and don't miss the high-scoring ones. The writer adds that their own best was 252 after 20 to 30 games, which is a useful reminder of how hard the game is.
Common mistakes
Subtracting for every missed dart. The penalty only applies when all three darts miss, and then only once. A round with one hit and two misses is simply plus the double.
Using the number instead of the double. Double 6 is worth 12, not 6. Both the reward for a hit and the penalty for a blank round use the double's value.
Forgetting the bull costs 50. A decent score going into the last round can take a large hit if all three darts miss the bull.
Keeping only a running total. A total tells you how the game went but not why. DartHelp suggests chalking each round separately, which is how you find a pattern of misses.
Tracking rounds to find your weak doubles
DartHelp's method is to write 1 to 20 and B down the side of the board with two columns per player, one for the points scored that round and one for the running total. After a few games you might notice you keep missing the 4s, or the 4s, 13s and 6s, which tells you the right side of the board needs work. That is the real value of the game: it shows you which doubles to practise next.
A phone can keep that record instead of the chalkboard. DartDrill's Bob's 27 routine lights the current double on a drawn board and takes one tap per round for how many darts went in, applying the same rules of starting on 27 and finishing at zero, with its scoring tested against the 1,437 maximum. Each logged round also feeds a heatmap that shades your weakest doubles, the same pattern DartHelp suggests finding with chalk.
Frequently asked questions
What is the highest possible score in Bob's 27?
1,437. That is three hits on every double from 1 to 20 (1,260), three bulls (150) and the starting 27.
Do you lose points for every dart you miss in Bob's 27?
No. You only lose points when all three darts in a round miss the target, and then you subtract the double's value once.
What happens if your Bob's 27 score goes to zero?
Under the usual rules the game is over. Because the score is always odd, it never lands on zero exactly; it ends the moment it goes negative. Some apps let you play on, or make elimination an option.
Is the last round of Bob's 27 the outer bull or the bullseye?
The bullseye, worth 50 per hit. Gran Darts calls it the double bull, and Decent Darts notes that missing it with all three darts costs 50.
Who invented Bob's 27?
It is credited to Bob Anderson, the Limestone Cowboy, who won the 1988 World Professional Darts Championship. DartHelp says he devised it purely to practise doubles.