james_schaefer (2) [Avatar] Offline
There's a bug in the code for the demos currently at badukai.
Fortunately, It's extremely easy to reproduce.

Unfortunately, it causes an error during the AI's turn, which block the AI from making a move, allowing the human player to move twice in a row...

Steps to reproduce:
1) during the AI's turn, predict where the AI will make it's next move.
2) hover over that position with your cursor.
3) if you guessed correct, an error will be thrown when the AI tries to make its move. A pop-up for the website says:

"www.badukai.com says:
Illegal move: Cannot play on existing stone!"

This is clearly an error, because there is no stone at this position, it's merely some strange interaction with the human-player's hover over. This error is by far easier to reproduce playing the 5x5 version of the demo, as the AI is more predictable, and the board space is smaller. However, I did unfortunately reproduce the issue playing a 19x19 game as well. A pity, since I found the game fascinating.
james_schaefer (2) [Avatar] Offline
On occasion during a 19x19 game, I observed a similar message during the AI's turn:

"suicide is not allowed"

I understand this bug much less, but it also effectively resulted in a pass by the AI.
KevinF (14) [Avatar] Offline
Thanks for the feedback, we'll try to hunt those bugs down!

BTW, you can also play against our demo bot on online-go.com now: https://online-go.com/player/540077/