Fifty-One By Fives

A game for any number of players, in which the winner is the first player to reach a score of exactly 51.  Players take it in turns to throw 3 darts, aiming for a total score that can be exactly divided by 5.  If a score can't be divided by 5, the score for that round doesn't count.  If the score is divisible by 5, it's divided by 5 to give the score.  A running toal for each player is recorded on the scoreboard.  If a dart misses the board completely, none of the darts in that round count.  The object is to score 51 exactly.  If a player's total score exceeds 51, all 3 darts in that round don't count and the score remains the same.