As for mixing it up, this is taken from the Deed of Gift:
In case the parties cannot mutually agree upon the terms of a match, then three races shall be sailed, and the winner of two of such races shall be entitled to the Cup. All such races shall be on ocean courses, free from headlands, as follows: The first race, twenty nautical miles to windward and return; the second race an equilateral triangular race of thirty-nine nautical miles, the first side of which shall be a beat to windward; the third race (if necessary) twenty nautical miles to windward and return; and one week day shall intervene between the conclusion of one race and the starting of the next race.
It looks like the Auld boys were thinking of putting a bit of variety in the mix, just a bit.
But this part today's fans would never go for:
...and each of such races must be completed within seven hours.