Go variant implementation

I have implemented xGo with help from AI. xGo has Go-like play, a global win criterion (no counting) and is elegantly balanced by the pie rule -- accomplishing the goals of Gonnect more beautifully. IMHO.

Basically, you play Go (with the pie rule) until both players pass, and then switch to Hex. There is a bit more information on wikipedia.

Interesting. Putting some of the wiki info into my own words: xGo has two phases: first a "Go" phase and then a "Hex" phase. Play in the Go phase proceeds exactly as in Go, and the phase ends after both players pass consecutively. The Hex phase begins immediately after the second consecutive pass, and play proceeds exactly as in Hex. The winning criterion for xGo is the same as Hex, connect two opposite sides of the board (one player is trying to connect horizontally, the other vertically).
. . .
And thus although the first phase proceeds exactly as in Go the objective during this phase would be different than a Go game. In Go the objective is to get more points (territory + komi) than your opponent, but in xGo the objective is to have your stones placed on the board in a manner that satisfies the conditions to win the game in the Hex (second and final) phase.

IMO, the name of the game should be Hex+Go. This game seems to me to be more of a Hex variant than a Go variant since the objective is to connect two opposite sides, and NOT to capture (claim/control) more territory as in Go.

I suggest you ( dushoff ) make this post in the Hex/Havannah forum also.

Hi, this is interesting, but how is this more elegant than Gonnect? In the latter, the goal of Hex is directly combined with the board and mechanics of Go, which seems to me more appealing than having two separate game phases using two different grids (maybe the actual play is better, but I cannot say without further try).

Elegance is in the mind of the player (just as beauty is in the eye of the beholder)... But to me, also having two different game phases is less elegant than having the same gameplay throughout the whole game.... And what is this (quoting eobllor ★ 20 hours ago) "using two different grids" thing? I don't remember seeing that in the wiki description, but I'll look at it again this weekend. Is phase 2 of xGo not played on the same board as phase 1?

Sighris, according to the on-line implementation, the Go phase is done on a standard goban, but the Hex phase adds the SW-NE diagonals to the grid, to make it equivalent to a Hex board.

There seems to be a minor bug, where if the go phase ends with a hex connection already in place, the program doesn't notice. It may depend on who passed last (in the game I tried, black passed, then white passed, and at that point, black already had a winning position).