Seats

A table's seats can be filled in two ways:

• every seat is a model.
• one seat is a model; the rest are engines.

The first approach is more like a real board game. Similarly to humans, the other seats sometimes play better, sometimes worse. This is not the case for engines. As a benchmark, though, the first approach isn't practical:

• one has to pick which models play in a game.
• if a game has multiple roles, every model has to play every role — and we pay for all the other models.
• to bench a newly released model, we have to pay for the other seats.

These problems don't exist when using the second approach. The second approach's problem is that the other seats don't vary; that can be mitigated by adding engines with different strengths or ones that sometimes slip.

The second approach is therefore preferred for future protocol versions.