@Almalexia, give Lex Luthor.Crassius "Biggus Dickus" Curio said:
You know how some BoPs set in modern times have the Olympics? Why not do that, but in Mesoamerica! And only one sport: the ballgame. Sometimes called pokatok, tlachtli, or ulama, the game had a lot of spiritual and ritual significance - but it was also just played for fun, by commoners and nobles alike. It involves a bouncing rubber ball - a technology which exists nowhere else in the world - but the exact rules of play are thought to have varied and are perhaps different from modern variants of the game. It is known that players wore protective padding and could use any part of their body but their hands to manipulate the ball.
Anyway it happens that there will be a ballgame championship every turn, first hosted by Tzintzuntzan (Curio) and from then on to be hosted by the winner of the last tournament.
Hosting the tournament begets a cash boost from travelers and pilgrims, as well as a happiness boost for all lineages. These bonuses scale with the level of your Ballcourts.
For the players, the results depend on your performance. Doing badly means maybe losing authority*, happiness, and prestige, performing well however means gaining some. The winner of course gets the most of these and goes on to host the next tournament with all the aforementioned benefits.
Performance in the tournament may depend on these factors (and possibly others): your own ballcourt level, your noble happiness, army professionalism, and some randomness.