Editing Life and death (section)

===Status of groups of four===
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{{Goban 11x11
| ul| uc| uc|  u|  b|  w|  b|  b|  b|  b| w
|  b|  b|  b|  b|  b|  w|  b|   |  c|  b|  w
|  w|  w|  w|  w|  w|  w|  b|  b|  c|  b|  w
|  b|  b|  b|  w|   |  w|  w|  b|   |  b|  w
|  l|  c|  b|  b|  w|   |  w|  b|  b|  b|  w
|  b|  c|   |  b|  w|   |  w|  w|  w|  w|  w
|  b|  b|  b|  b|  w|   |   |   |   |  |  r
|  w|  w|  w|  w|  w|  w|  w|  w|  w|  w|  w
|  w|  b|  b|  b|  w|  w|  b|  b|  b|  b|  w
|  b|  b|   |  b|  b|  w|  b|   |   |  b|  w
|  b|  d| dc|  d|  b|  w|  b|  d|  d|  b| w|20}}
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Groups with four empty points
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With four blank spots, there are [[tetromino|five unique shapes]]. Three are alive, one is unsettled, and one is dead.

The three alive ones are the straight line, L and Z shape. If the opponent plays in any spot, the first player can live by playing in the adjacent spot in the center two. In the diagram "Groups with four empty points" black's groups in the upper corners are alive. If the opponent plays any of the circled positions, playing the other circled position will secure the status of the black group.

The unsettled shape is the four-stone pyramid, shown in the left bottom corner. Whoever plays in the circled center spot gets the desired result, so the player whose move it is wins.

A two-by-two square space is dead: if black plays in the top left corner of the two-by-two square, white can respond by playing in the bottom right corner (see the L-shaped case in the previous section). On the other hand, if white wants to capture the black group, they only have to play anywhere inside the square, and there will be no way for black to avoid capture.