New Scientist Enigma 966 – Prime Tennis
by Richard England
From Issue #2121, 14th February 1998
At tennis a set is won by the first player to win 6 games, except that if it goes to 5 games all it is won either 7 games to 5 or 7 games to 6. (As far as this puzzle is concerned this applies even to the final set).
The match that we are considering went to 5 sets and no two sets contained the same number of games. At the end of each set the total number of games played up to that point was always a prime number. From this information the score in one or more of the five sets can be deduced with certainty.
Which set or sets had a score that can be deduced with certainty, and what was the score in the set or each of the sets concerned?