This was a disturbingly violent game, in which the losing team was often decapitated. Ritual killing was a big part of Mayan culture and tradition.
According to Atlas Obscura,
The Aztecs continued this proud tradition of loser‐lose‐all, as many vases and sculptures depict the inevitable decapitation of the losing team. There are even some depictions of ball players playing with the heads of the losers in place of a ball. Whether this actually occurred is up to artistic speculation. The Spanish who observed the game reported horrendous injuries to those who played it — deep bruising requiring lancing, broken bones, and even death when a player was hit in the head or by an unprotected bit by the heavy ball. (https://www.atlasobscura.com/articles/meso-american-baseball)