It's a complicated solution for a problem that doesn't really exist.
How the port/starboard entries are allocated for the America's Cup races have become a bit of a head-scratcher for casual observers and seasoned sailing followers alike as weather delays and postponements have put the system out of sync.
The trick to getting your head around the system is to think of it in terms of time-slots rather than days. The choice of who gets port entry for each race alternates each day.
For example, if Team NZ gets first choice at entry for the earlier 8.15am race, Oracle gets to pick what side they enter from in the later race. The following day it swaps, so Oracle get first dibs on the early, race and Team NZ the second race of the day.
Where is gets confusing is when the second race of the day is not sailed as we have seen over the past few days. The allocation of port entry from the first race keeps alternating as usual, but the second race carries over.