This game was devised by Bob Anderson and concentrates on Doubles accuracy. The game starts with a score of 27 and you should throw 3 darts at each double in ascending order, starting from D1 and all the way up to D20. Add the value of the double with each hit, and deduct the value of the double if you miss all three darts.
For example, if a player hit D1 three times in the first round, he would add 6 (3 × D1) to 27 and the new score would be 33. However, he missed all three darts in the next round, 4 (D2) would be deducted from 33 and his score would now be 29.
The game finished when the score reaches zero.