Just played a bunch of Bohnanza 4 players and what occurred to me this time around is that card counting is significantly more valuable in the game than it initially appeared to me. There's a fixed number of each sort of card in the game--and every card lists how many of its card type is around. So many of the card type are on the tableau face up, so many (a known quantity) in the discard pile, so many (a known quantity) permanently vapourized from the game, so many are in your hand (which you can obviously see), and then there are unknown quantities in other players hands and in the draw pile. Because trading is a huge element of the game, player hands are not exactly an unknown quantity, so you can reasonably determine if any are in other players hands. So card counting is very valuable in determining the odds of certain card types coming up in future draws.
There's one card type that there's only 6 of. I had vapourized 3 and had 1 in my hand. Another player played 1 and then spent most of the game pursuing others; That was a dumb strategy, because it would have been astronomically unlikely for him to get them.
For more strategic play, this hurts the game. Imagine playing against an AI that counted cards perfectly; even without accounting for particularly good strategy, card counting alone would make an AI beat most humans.
Of course the second major mechanic in Bohnanza is trading, so skilled play also results in a no-cooperate trade strategy as other players gang up against you. Especially since one of the major trade types in Bohnanza isn't getting cards you want, but rather donating cards you don't want--so others can easily stonewall you by denying your donations in order to burn you. I suspect the optimum trade strategy is PASSIVE PLAYER/RECIPIENT 1) Do not cooperate. 2) Accept trades that significantly benefit you. 3) Only accept donations if they significantly benefit you, preferring to burn other players rather than take moderate help. ACTIVE PLAYER/INITIATOR 1) Always try to trade away and be as friendly as possible, but I haven't written an AI for this yet so I'm not sure.
I've had the game for a few years now and played a lot of rounds, but I think it's definitely settled into the "casual fun" territory because mechanically these limit a lot of the strategy that could arise.
