Beginner's Corner Solution

Was the reader able to find the vital point of black 1 in Diagram 4? Notice that this move creates a shortage of liberties for white's stones. After black plays at 1, white can do nothing to take advantage of black's own shortage of liberties, and black has all the time in the world to capture white. Notice that if white captures at white 2, black must play at 3 to maintain the shortage of white's liberties. White cannot block to the right of black 3 without putting the whole group into atari

Diagram 4

Incidentally, black 1 in Diagram 5 is a failure. Although the move does create a shortage of liberties for white, it does nothing to alleviate black's own shortage of liberties. White takes advantage of this to play at 2, initiating a ko fight. If black could connect 1 to the rest of the black group, white's group would be put into atari, but this is impossible. As before, black's shortage of liberties would result in the black group itself being put into atari.

Diagram 5

Notice also that a black move at 2 in either of the above diagrams would be useless, since it would not create a shortage of liberties for white. This fact is pointed out simply for the sake of thoroughness: it is the last of the four points that may be played in the corner alluded to on page 12. Shortages of liberties are quite common in the game of go. When one learns to anticipate the possiblity of a shortage of liberties coming into play, one increases one's strength considerably. Life and death problems are particularly good for developing such perception.