That is an interesting idea, but the blacklisting idea might work, maybe half baked. If you had a very big group in Atari, you would pretty much have to make that move every other turn, which could get old, I kind of expect that it would work itself out, eventually there would be more than one large group in Atari, but then the players would cycle, back and forth.

Maybe instead of a blacklist, introduce a third type of token to mark co-selection. The token when placed on a cross hatch would reduce all connected liberties, and generally behave like an edge. That way you wouldn't get Atari cycles, since the other player couldn't prevent capturing.

eventually there would be more than one large group in Atari, but then the players would cycle, back and forth.

Ahh, but they wouldn't cycle. The moves are made concurrently, so they don't know which move the opponent will pick.

Half the time, they will both choose the same move, blacklist it, then blacklist the remaining move, then tenuki. But the other half the time, they will choose different moves, resolving both groups in one turn.

Maybe instead of a blacklist, introduce a third type of token to mark co-selection. The token when placed on a cross hatch would reduce all connected liberties, and generally behave like an edge. That way you wouldn't get Atari cycles, since the other player couldn't prevent capturing

Ahh, but they wouldn't cycle. The moves are made concurrently, so they don't know which move the opponent will pick.

Half the time, they will both choose the same move, blacklist it, then blacklist the remaining move, then tenuki. But the other half the time, they will choose different moves, resolving both groups in one turn.

What if these internal edges behave like a wild stone, either black or white? That is, if black is surrounded by white and wild stones, he's captured. If a wild stone is surrounded by one color it's captured. If a wild stone and a black group are connected and all surrounded by white, they all are captured.

What if the blacklist continues until legal moves are played? So move 100 (same spot, blacklisted) move 101 (same alternate spot, so spot 100 & 101 are blacklisted) move 102 (different locations, so all blacklists cleared).

Does that mostly solve the problem at AMA level?

Does anyone have any analysis or details on games of Go played concurrently? Not simultaneous games against multiple people, but when both players "seal" their moves and play at the same time. If they pick the same space, then that spot is blacklisted. Captures get resolved simultaneously (so a seki might end up getting both groups killed).

I think it'd destroy a lot of the current gameplay, but would it produce anything neat? My biggest concern is that it'd become a game of guessing what the other person wants, introducing chance.

I looked on SL, but couldn't find anything. Any insights?

You could have players bid for the move, both players revealing their bids and plays at the same time. The high bidder pays the difference in bids to the other player. (All bids must be non-negative.) If both players pick the same point to play on, the high bidder plays and pays the other player the amount of his bid. If both players pick the same point and make the high bid, flip a coin, or let the players alternate. The first time that happens, Black makes the play and pays the price, the next time White does so, etc. Each player's final score is the regular go score plus the points he has been paid.

You could have players bid for the move, both players revealing their bids and plays at the same time. The high bidder pays the difference in bids to the other player. (All bids must be non-negative.) If both players pick the same point to play on, the high bidder plays and pays the other player the amount of his bid. If both players pick the same point and make the high bid, flip a coin, or let the players alternate. The first time that happens, Black makes the play and pays the price, the next time White does so, etc. Each player's final score is the regular go score plus the points he has been paid.