Badminton

A badminton game is won by the first player to reach 21, unless both players reach 20, in which case it is won by the first player to get 2 points ahead.

In a particular match, which was best of three, players a and b won one game each, so a third deciding game had to be played.

For each of the players, the number of points they won in the three games, taken in game order, formed an arithmetic progression, with a non-zero common difference.

What was the score in the final deciding game?

27 - 25
21 - 23
15 - 21

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Originally posted by Thomaster
27 - 25
21 - 23
15 - 21

Like this?