1997-5-3 last update, 1997-2-4 first day, Robert Jasiek

These very simple and logical go rules are known as Tromp-Taylor rules.

square grid

- This grid has 9x9 grid points.
- Paths of grid lines are between any two grid points.
- This is the outset.
- The game is played by two players. Each player has a color: black respectively white.

grid points with colors black, white, or empty

- Two players compete using black respectively white color.
- Grid points without black or white have empty color.

grid point A reaches white

- A path along grid lines leaves the grid point A, passes the squared grid points, and ends at the triangled grid point.
- The grid points A and squared all have the empty color of A.
- The triangled grid point has white color.
- The grid point A reaches white.

A, B, C reach white

- Each of the grid points A, B, and C reaches white.
- The grid point D does not reach white.
- All four grid points reach empty.
- B, C, and D also reach black.
- A does not reach black.

A reaches black

- The grid point A reaches black using a short path.
- A also reaches empty.

clearing black

- The black grid point near to white grid points does not reach empty. Thus it is to be cleared.
- After clearing the grid point is empty.

clearing black

- Several black grid points do not reach empty. They all become cleared.
- After clearing the grid points are empty.

black starts, then both players alternate

white's turn is a move at 1

- Most turns are used for a move.
- White uses his right to move by coloring the empty grid point 1 white.
- Black needs no clearing then.
- White needs no clearing then, either.
- Often no clearing at all occurs.

white's turn is a move at 1

- White moves at 1, making the empty grid point white.
- Then black is cleared: One black grid point becomes empty.
- Then white needs no clearing.
- A move can include clearing of one color only.

white's turn is a move at 1

- White moves at 1, making the empty grid point white.
- Then black is cleared: Several black grid points become empty.
- Then white needs no clearing.

black's turn is a move at 1

- Black moves at 1, making the empty grid point black.
- Then white needs no clearing.
- Then black is cleared: Three black grid points become empty.
- Such suicidal clearing rarely occurs.

2 repeats an earlier grid coloring and is not allowed

- If black played at 2 after white's 1, then the grid coloring before 1 would be repeated.
- Black may not play at 2 right now. He is required to use his turn differently.
- Black might get a chance to play at the grid point 2 later.

white's turn 1 is a pass - black moves at 2 - white's turn 3 is a pass - black's turn 4 is a pass

- White has the turn but no useful move. Therefore white uses his turn 1 to pass.
- Black still has a useful move: he moves at 2.
- Black 2 is the last move coloring a grid point.
- Black 2 prepares the grid for scoring by clearing white.
- After 2 no player can increase the number of empty grid points that do not reach the opponent's color.
- The turns 3 and 4 are both passes. They are played consecutively and thus end the game.

black score - white score

- The black score consists of the black grid points and the empty grid points not reaching white.
- Black's score is 40.
- The white score consists of the white grid points and the empty grid points not reaching black.
- White's score is 41.
- White has the higher score and wins the game.

black score - white score

- Black's score is 44.
- White's score is 35.
- Black has the higher score winning the game.
- The two empty grid points reaching black and white score for neither player.