Xuanxuan Qijing · Problem 40
Xuanxuan Qijing · Problem 40. Go, Black to play. Study 11 reference plies, try both sides and branch from the replay.
Site coordinates run A–S left to right and 1–19 top to bottom; A1 is the top-left intersection.
Read the position, one decision at a time
Try the position first, then open the notes. They explain measurable changes in the reference, not every possible variation.
Reveal step-by-step explanations
1. Black · O16
This move captures 0 stones. After captures, the connected group containing the new stone has 4 stones and 5 liberties: N16, Q16, P18, Q17, Q15. Diagonal neighbours are not part of the same group. More than one liberty does not by itself establish life; examine the next move.
2. White · N16
This move captures 0 stones. After captures, the connected group containing the new stone has 6 stones and 3 liberties: M16, N18, O18. Diagonal neighbours are not part of the same group. More than one liberty does not by itself establish life; examine the next move.
3. Black · M16
This move captures 0 stones. After captures, the connected group containing the new stone has 4 stones and 4 liberties: L17, K16, K15, M18. Diagonal neighbours are not part of the same group. More than one liberty does not by itself establish life; examine the next move.
4. White · P18
This move captures 0 stones. After captures, the connected group containing the new stone has 1 stones and 3 liberties: P19, O18, Q18. Diagonal neighbours are not part of the same group. More than one liberty does not by itself establish life; examine the next move.
Understand this position
19 ranks × 19 files · 9 black stones · 9 white stones
Count the liberties of each connected group, not the empty points next to just one stone. Orthogonal contact connects; diagonal contact does not. Try your move, count captures and recount the resulting group’s liberties before comparing the reference.
Read the reference line (11 plies)
Coordinates match this board: letters left to right, row numbers from top to bottom. These are board coordinates, not traditional score notation.
- Black
O16 - White
N16 - Black
M16 - White
P18 - Black
O19 - White
M18 - Black
N19 - White
P19 - Black
Q18 - White
M19 - Black
Q19