Mistakes made by professional Go players
The problem The official solution XuanXuanGo's discovery Black to play first Diagram 1 Diagram 2 This is a problem by Go Seigen. The problem is a mistake, the white stones actually can never be killed. In solution diagram, white 4 is a bad move which results in white's death. Black 1 should play at 6, this is the strongest move, however, white can still Seki. XuanXuanGo thinks white 4 should play like diagram 2, white stones won't be killed. If black 5 plays at 6, white plays at 5 and lives. Time used by XuanXuanGo to solve this problem: 4.10 seconds
The problem The official solution XuanXuanGo's discovery XuanXuanGo's solution White to play first Diagram 1 Diagram 2 Diagram 3 This is a problem by Honinbo Shusai. For the official solution (diagram 1), the book says if black plays at A, then white plays at B, black dies. Here, Shusai neglected black's playing at C to have a Ko, as demonstrated in Diagram 2. XuanXuanGo thinks diagram 3 is the correct solution, in which black is killed unconditionally. Time used by XuanXuanGo to solve this problem: 6.14 seconds
The problem The official solution XuanXuanGo's discovery Black to play first Diagram 1 Diagram 2 This is a problem by Go Seigen. In diagram 1, white 8 is a bad move, which results in the white's unconditional death. If white 8 plays like diagram 2, white will have a hope to live by Ko. Time used by XuanXuanGo to solve this problem: 0.30 seconds
The problem The official solution XuanXuanGo's discovery Black to play first Diagram 1 Diagram 2 This is a problem by Go Seigen. In the solution diagram, white 2 is a fatal mistake, white is killed unconditionally. If XuanXuanGo plays white, it would play like diagram 2, white can have a Ko. If black 5 plays at 6, white plays at A, living without a Ko. Time used by XuanXuanGo to solve this problem: 0.45 second
The problem The official solution XuanXuanGo's discovery Black to play first Diagram 1 Diagram 2 This is a problem by Maeda Nobuaki. The problem is a mistake, the white stones actually can never be killed. In solution diagram, white 4 is a bad move which results in white's death. XuanXuanGo thinks white 4 should play like diagram 2, white stones won't be killed. Later, white lives if get either point. Time used by XuanXuanGo to solve this problem: 0.15 second
The problem The official solution XuanXuanGo's discovery Black to play first Diagram 1 Diagram 2 This is a problem by Maeda Nobuaki. The problem's official solution has a mistake, the white stones actually can't be killed unconditionally. In solution diagram, white 2 is a bad move which results in white's death. XuanXuanGo thinks white 2 should play like diagram 2 and white 4 is an amazing tesuji, white lives by Ko. Time used by XuanXuanGo to solve this problem: 29.00 seconds
The problem The official solution XuanXuanGo's discovery Variation
Black to play first Diagram 1 Diagram 2 Diagram 3 This is a problem by Hashimoto Utaro. The problem is a mistake, the white stones actually can't be killed. In solution diagram, white 2 is a bad move which results in white's death. XuanXuanGo thinks white 2 should play like diagram 2, white lives. If black 7 plays at 8, white plays at 7. Diagram 3 is a variation, if black plays at 3, white can also live. Time used by XuanXuanGo to solve this problem: 0.50 seconds
The problem The official solution XuanXuanGo's discovery Black to play first Diagram 1 Diagram 2 This is a problem by Hashimoto Utaro. The problem's official solution has a mistake, the white stones actually can't be killed unconditionally. In solution diagram, white 2 is a bad move which results in white's death. XuanXuanGo thinks white 2 should play like diagram 2, white lives by Ko. Time used by XuanXuanGo to solve this problem: 0.25 second
The problem The official solution XuanXuanGo's discovery Black to play first Diagram 1 Diagram 2 This is a problem by Hashimoto Utaro. The problem's official solution has a mistake, the white stones actually can't be killed unconditionally. In solution diagram, white 2 is a bad move which results in white's death. XuanXuanGo thinks white 2 should play like diagram 2, white lives by Ko. After white 2, black 3 is the strongest move, if plays anywhere else, white will live unconditionally. Time used by XuanXuanGo to solve this problem: 47.25 seconds
The problem The official solution XuanXuanGo's discovery XuanXuanGo's solution
B to play first Diagram 1 Diagram 2 Diagram 3 This is a problem by Sato Sunao. The problem's official solution has mistakes, In the solution diagram, black 3 is a mistake, however, white 4 is a mistake too. After black 3, white can kill black as diagram 2. XuanXuanGo thinks black 3 should play like diagram 3, black will have a Ko to live. After white 6, black cannot play at A, as white will play at B to kill. Time used by XuanXuanGo to solve this problem: 12.90 seconds
The problem The official solution XuanXuanGo's discovery Black to play first Diagram 1 Diagram 2 This is a problem by Kaku Kyushin. The problem is a mistake, the white stones actually can't be killed anyway. In solution diagram (black 3 plays at 8, white 14 plays at A and black 15 plays at 13), white 4 is a bad move which results in white's death. XuanXuanGo thinks white 4 should play like diagram 2, white lives. Time used by XuanXuanGo to solve this problem: 3.60 seconds
The problem The official solution XuanXuanGo's discovery Black to play first Diagram 1 Diagram 2 This is a problem by Lee ChangHo. The problem's official solution has a mistake. In solution diagram, black 3 is not a strong move. Actually, black can kill white unconditionally, if black 3 plays like diagram 2. Time used by XuanXuanGo to solve this problem: 0.15 second
The problem The official solution XuanXuanGo's discovery XuanXuanGo's solution
White to play first Diagram 1 Diagram 2 Diagram 3 This is a problem by Lee ChangHo. The problem's official solution has mistakes, In the solution diagram, white 3 is a mistake, however, black 4 is a mistake too. After white 3, black 4 can kill white as diagram 2. XuanXuanGo thinks white 3 should play like diagram 3, white will live. If black 6 plays at 7, white 7 plays at 6. Time used by XuanXuanGo to solve this problem: 48.90 seconds
