On brainking.info, Fencer says that he plans to three games that make up Tavli. Portes is one of them, and he says Brainking has it already, because it's just backgammon without the doubling cube. That's not quite correct. The rules of Portes state that the winner of the opening roll rerolls. A subtle difference, meaning that the player going first may start with doubles, which is impossible in regular backgammon. (There's also a slight difference in counting points, but that's only relevant for point matches).

Of course, it means that implementing Portes will not be difficult, as it's almost the same. Just not exactly.