By the way, if anyone's interested in learning to play Jetan, pick up "The Chessmen of Mars," by Edgar Rice Burroughs - it's part of his "John Carter of Mars" series. There's an appendix in the back detailing the board, pieces, and rules, including traditional Barsoomian Jetan customs like always placing the orange army towards the north and the black army toward the south, as the game represents a battle between the Yellow Men of the North and the Black Pirates of the South.
One of my favorite things about Jetan is that the strategies change during the course of the game. In chess, once you're down a handful of pieces compared to your opponent, it's very difficult to recover. In Jetan, if anyone other than the Chieftain (King) captures the enemy Chieftain, it's a draw, regardless of the number of the respective armies. So when your army is half the size of your opponent's, that just means you can bring your Chieftain out into reckless combat, because your opponent (who has numerical superiority and is after a clean win) isn't going to want to attack your Chieftain with any of his other pieces and bring about a draw. So he's got to keep his Chieftain protected from all of your pieces (because you'll take a draw over a loss any day), while you're under no such constraints.
The other thing I like is that there's no such concept as "check." After all, "check" is basically saying to your enemy Chieftain/King, "Excuse me, but I'm about to kill you next turn if you don't stop me. You might want to do something about that." In Jetan, if the Chieftain doesn't see the attack coming, then too bad for him!
Johnathan