Three races are scheduled each day, Saturday and Sunday. Provisional races will will be sailed on Friday. Remember that in Chicago Team Japan’s win in the provisional race was counted when no races could be sailed in Saturday’s light winds. Sunday’s racing counts double points, meaning that last place on Sunday is as valuable as first place on Saturday.
The courses can be anywhere from four to ten legs long, always with a reaching start following by a series of windward-leeward legs and then a reach or short downwind leg to the finish, from either a mid-course rounding mark or the last gate. The diagram is a bit confusing, since it shows virtually all the options for the final leg to the finish.
Here’s a video that explains the course and some of the tactics. A few things have changed since I made this video but the basics are all the same.