Tichu Pass Convention (developed by Aaron D. Fuegi (aarondf@bu.edu) and Andy Latto) First, to cut to the chase, here is the pass convention I recommend using: Card Passing To Opponents (3-5-7-9-J-K-A-Q-10-8-6-4-2) 0) Choose the cards to pass based on what will help your hand the most but when you actually choose who to give what, apply the following rules: 1) When passing an even and an odd card to the opponents, always pass the even card to the player on the right (treat Jacks and Kings as Odd and Aces and Queens as even for this purpose). 2) When passing two non matching EVEN cards, pass the LOWER one to the player on the right. When passing two non matching ODD cards, pass the HIGHER one to the player on the right. 3) When splitting a pair, pass the higher alphabetically named suit card to the right (thus Red, Green, Blue, Black). 4) When passing only one card of a pair, take suit into account (based on your other cards in your hand, try to make it less likely you are filling straight-flushes when passing to the opponents and more likely when passing to your partner). Note that I assume here that players are playing in the standard Western clockwise order where each player is followed by the player on his left. Thus, left really means "player who plays after you" and right really means "player who plays before you". Make sure that both you and your partner understand this. If two players were to try to both play the convention above, but one were to reverse the direction, it would greatly _worsen_ the problem it is trying to solve. Ok, why is the above a good idea? This actually comes down to two separate questions. The first is, should there be any convention to the pass? The second is, if there is a convention, what should it be? 1) Should one impose a convention on what one passes or just decide randomly? Sometimes you and your partner pass the same rank to opponents (for example, you are each passing a 3). When this happens, it is preferable to pass this rank to different opponents; this reduces the chances of creating groups of the cards you are passing and guarantees neither opponent will have 4 of a kind in this rank (a bomb). It turns out that, if one considers all card passes equally likely (that is; that one is just as likely to pass a King as a 2), then all conventions (such as the one above versus "low to the left") achieve the same thing. With no convention, the chances of both partners (randomly) passing the same card to one person are 15.38%. With a convention, the chances are 9.4% (about 60% as likely). 2) Ok, I accept that a convention is good but what convention is best? To understand this, one needs to understand what a convention is doing. All conventions (for this purpose) are simply imposing an ordering on the cards. For example, "low to the left" imposes the ordering 234..QKA and has you pass the card farthest to the left on this ordering to the left. Note the effects this achieves. The player on your right can Never receive a 2 unless you split a pair of 2s. Similarly the player on your left can Never receive an Ace unless splitting a pair of Aces. This guarantees that neither of those two players will ever receive two 2s or two Aces unless one player split 2s or Aces and, if this is the case, that means that the player getting two 2s does NOT have all 4 of them. It also turns out that while it is possible for a player to receive two 3's or two Kings, this is also very unlikely as I will only ever pass a 3 (without splitting a pair) to the player on my right if I pass a 2 to the player on my left. Ok, how could this "low to the left" plan be improved upon? First, we can probably make the reasonable assumption that we are going to be most commonly passing low cards and so those are the ones we particularly want to avoid passing pairs of to a given player (i.e. since I'm never going to pass my opponents an Ace, I really don't need to worry much about what happens if both I and my partner are passing Aces to the opponents). This suggests the ordering we choose should start with a 2 and end with a 3 (or vice versa). Take this a little further and we realize that what we want is an ordering that has the lowest cards as far towards the ends of the ordering as possible and higher cards in the middle. Based on these rules, we have a choice of: (3-5-7-9-J-K-A-Q-10-8-6-4-2) or (2-4-6-8-10-Q-A-K-J-9-7-5-3). These are basically equivalent and we choose the former for a couple of minor reasons: 1) I think people equate "even with right" more than "odd with right". 2) If passing two cards at equal points on the scale (3-2, or 7-6), the higher goes to the left. This is slightly better as if I use the 1/Mah Jong power, I will deprive the player of a slightly higher card. The suit ordering rule (#3 at the very top) is basically just an extension of the card ordering rule. It will only ever matter if both you and your partner both split pairs and, similar to the rank ordering, it will reduce the chances of filling straight flush bombs in this rare situation.