How to know when you can end the game
The game ends when both players pass consecutively but a lot of beginners have trouble knowing when the game is over and they can both pass. In short, both players should pass only when there are no moves left that either:
- Increases your territory; or
- Reduces your opponent’s territory
Below, I will demonstrate how to successfully wrap up a game to be ready for scoring.
The position shown on the right is coming to a close but the game hasn’t finished yet. In fact, there are 4 endgame points that still need to be played.
To start, let’s examine the bottom-left corner.
If white completely encloses the corner, white has 9 points there.
However, if black pushes in at 1, white must defend their territory at 2.
This puts black’s stone at 1 in atari (in danger of being captured), so black must defend at 3.
Once black has defended, black is threatening to capture white’s stone at 2 so white defends at 4, making a tiger’s mouth.
If you can’t see why white must defend after black 3, feel free to try find the variation on your board.
Now the position is settled and white’s bottom-left corner only has 7 points. White has lost 2 points because black has pushed in at 1.
Because black has the ability to reduce white’s points with 1, black should not end the game yet.
If black did push in as above, we can count 8 points in that block in the top-left corner. Keeping that space in mind, let’s see what happens when white pushes in first.
When white pushes in at 1, black must defend at 2, which puts white’s stone in atari.
White will save the stone with 3.
Now black only has 7 points in that same area instead of 8, so white has taken 1 point away from black.
But don’t forget that, because white played first, white doesn’t have to place stones at the triangles, thus saving white 2 points.
So both players will be eager to get to this (and every other) endgame point first!
The center point is no different. If black plays first, they have a point at the triangle.
But if white plays first, that point is gone.
Whoever gets this point first effectively makes 1 point.
The right side is a bit more complicated.
If white plays first, white must capture at 1, black can push in at 2 and white will block with 3.
White blocking with 1 at 2 would not go well. See if you can find out why.
With white gone first here, white has 8 points in the corner (7 + 1 prisoner captured at the triangle).
If black plays first, white only has 7 points in the corner (6 + 1 prisoner captured at 4).
So the “swing” of this corner is 1 point.
Let’s look at another position, where 2 additional factors will be introduced, dame and invading.
With what you’ve learned so far, you might think that only the top at D9/E9 needs to be played before ending the game but there are nuances to consider.
Let’s ignore the triangle near the bottom-right for now.
When black closes up the top, that leaves the dame (“dah-meh”) points left. We can see 3 in this game.
Unlike the sequence at the top, dame points are worth nothing to either player.
For completeness sake, it is recommended that beginners fill in dame points at the end of the game for reasons I won’t get into here.
This can also aid as a guide in case you don’t know what to play next when finishing the game. Just look for a point that is not “flush” against your opponent.
You can end the game after filling in the dame but black here has decided that white’s territory is so big, that black can invade and live in there.
Successfully living inside white’s territory will wipe out a lot of white’s points and be devastating so white must kill it.
Invasions like this are worthwhile if you believe you can live in their area, otherwise it’s best to leave it alone. For example, white trying to live in black’s area here would be absolutely impossible and a waste of black’s time.
Black dies here but it’s worth a try. Black has lost no points because, although white has gained 4 additional points in the form of prisoners, white has also lost 4 points because they were forced to play in their own territory.
However, if black lives, half of white’s area has been erased.
Now, new endgame points have risen (at the triangles) that need to be played through. Then the game can be ended.
That’s all for finishing the game. Remember, if you don’t know how to finish the game, play dame.
I’ll also mention as a footnote: These lessons are done for Japanese rules. Chinese rules counts both area and stones as points so playing a dame point in Chinese rules is actually worth 1 point. You shouldn’t have to worry about it though.