What are the rules of Bob's 27?

You start on 27 points and throw three darts at each double in turn, double 1 to double 20 and then the bullseye, 21 rounds in all. Only the double counts. Each hit adds its value, so double 7 is worth 14 and the bull 50. A round with no hit takes that value off your score, once. If a round leaves you below zero the drill is over, and your score is wherever it ended.

What is a good score in Bob's 27?

Getting through all 21 rounds without going below zero is a good session for a casual player. Around 400 is a solid league standard, and scores in the 600s are exceptional. The most anyone can score is 1,437.

Do you lose points for every missed dart in Bob's 27?

No. A round with no hit takes the double off once, however many darts missed. Three misses on double 10 cost 20. One hit and two misses on double 10 add 20 and take nothing away.

Is it out at zero or below zero in Bob's 27?

It makes no difference. You start on 27, an odd number, and every double is worth an even number, so the score is always odd and can never be exactly zero. Below zero is the only way out.

Why is it called Bob's 27?

It is named after Bob Anderson, who devised it, and the 27 points it starts on.

Bob's 27

What is Bob's 27?

A doubles practice drill for one player. You go round every double on the board, from double 1 to double 20 and then the bull, and the score at the end says how well your doubles held up. It takes about fifteen minutes and needs nothing but a board.

Play it now

PracticeKept out of your match figures, and kept in your Practice area.

Score. Higher is better

Round 1 of 21

worth 2

Each D1 adds 2. A round with no hit costs 2 and leaves 25.

Only the double counts. No visit totals in this drill

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Getting the board ready

Twenty-one rounds of doubles, a score that starts on 27, and a run that ends the moment you go below zero. Tap each dart as it lands. Before every round the board says what a blank would cost and whether it would end the run, and if you mis-tap a round three doubles back, tap it in the list below the board and the whole run is worked out again.

How it is scored

Only the double of the round's number counts. A single 5 or a treble 5 in the double 5 round is a miss, and so is a double 6. On the last round only the bullseye counts; the outer bull is a miss and costs 50.

The early doubles are worth so little that a slow start is dangerous. Miss everything and this is what happens:

Round	A blank costs	Score after
D1	2	25
D2	4	21
D3	6	15
D4	8	7
D5	10	−3

Still alive on 7 after double 4, out on −3 after double 5, fifteen darts in. One hit anywhere in those five rounds and you would have reached double 6.

Finish on the bull: Every published maximum assumes it. Turn it off and the drill ends at double 20, with a best possible score of 1,287.
Play on below zero: With it on you throw every round whatever happens, which suits anyone put off by early exits. The score means something different, so it is only ever compared with other play-on runs.

What the numbers say

If most of your runs die before double 6, it is the small doubles beating you, and they hardly ever come up when you are finishing a real leg. Try 420 for a while instead. It works round the same doubles but never ends early, so every session gets you to double 16 and double 20, which are the ones that win legs.

Questions

What are the rules of Bob's 27?: You start on 27 points and throw three darts at each double in turn, double 1 to double 20 and then the bullseye, 21 rounds in all. Only the double counts. Each hit adds its value, so double 7 is worth 14 and the bull 50. A round with no hit takes that value off your score, once. If a round leaves you below zero the drill is over, and your score is wherever it ended.
What is a good score in Bob's 27?: Getting through all 21 rounds without going below zero is a good session for a casual player. Around 400 is a solid league standard, and scores in the 600s are exceptional. The most anyone can score is 1,437.
Do you lose points for every missed dart in Bob's 27?: No. A round with no hit takes the double off once, however many darts missed. Three misses on double 10 cost 20. One hit and two misses on double 10 add 20 and take nothing away.
Is it out at zero or below zero in Bob's 27?: It makes no difference. You start on 27, an odd number, and every double is worth an even number, so the score is always odd and can never be exactly zero. Below zero is the only way out.
Why is it called Bob's 27?: It is named after Bob Anderson, who devised it, and the 27 points it starts on. Source: Bob Anderson on X