Go

How to play Go

From the book's pages

• Two players, black and white, on a board with 19 vertical and 19 horizontal lines. The stones are placed on the intersections, 361 in all. The nine marked points are used only for handicaps.
• The board is empty when the game begins. Black places first, then they alternate. A stone once placed is never moved. A player may pass instead of placing.
• A stone has as many liberties as it has empty neighbouring points along the lines: four in the middle of the board, three on the edge, two in the corner. Stones of the same colour on neighbouring points form one chain, and the chain lives or dies as a unit.
• A stone or chain is captured when it loses its last liberty. It is removed at once and set aside as a prisoner. There are no diagonal lines in Go.
• Suicide: a stone cannot be placed on a point where it gets no liberty — unless it takes the opponent's last liberty at the same time; then it captures.
• Eyes: a group with two surrounded, empty points cannot be captured, since the opponent cannot place in either of them.
• Ko: when a capture would give the position that stood before the previous capture, another move must be made first.
• Seki: where neither can attack without putting themselves in danger, the stones stay standing, and neither gets the area.
• Points: the territory, the empty points you have surrounded, plus the stones you have captured. Stones left standing that cannot be saved are prisoners and count as captured when the game is over.
• Handicap: the weaker player gets 2–9 black stones on the marked points — two on d4 and q16, three with q4, four with d16, and so on up to nine — and white places first afterwards.

My choices

What the book does not say, or says for a board with stones in hand, has been filled in like this.

• The game is over when both pass in turn. Then you mark the dead groups by pressing them (the machine suggests), and «Count up» counts as the book does: prisoners plus territory. If you disagree, «Play on».
• No komi, since the book has none; 6.5 to white can be chosen.
• 9×9 and 13×13 alongside 19×19. The book uses 13×13 for its examples and says it can be used for shorter games.
• The machine plays on random playouts (Monte Carlo). It is a beginner on 9×9 and weaker the larger the board; on 19×19 it is mostly for trying out the rules.
• «Strong — GNU Go» hands the machine's moves to GNU Go 3.8, a separate program that runs in your browser and is free software under the GNU General Public License (its source is at gnu.org/software/gnugo). It is a real club player; the first move takes a few seconds while it loads.
• On a crowded board the first press places a transparent stone, and a second press on the same point places it.

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