Probing the Subtle Depths

"Probing the Subtle Depths" is a Xiangqi (Chinese Chess) puzzle from the collection Chariot & Horse mates. Red moves first and wins in 30 moves; the key first move is R8=5. Below you will find the full solution, what each move achieves, where it could go wrong, and the alternative defences.

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Pieces on the board

Red has a General, a Chariot, a Horse. Black has a General, a Chariot, 2 Soldiers.

Solution move by move

1. Red R8=5 (check)
1. Black K5=6
1. Black K5=6
2. Red H3+5 (check)
2. Black K6+1
2. Black K6+1
3. Red H5+6 (check)
3. Black K6-1
3. Black K6-1
4. Red R5=1
Why it works–
What to watch out for
Not forcing: the defender has 18 replies, so compare each one before playing it.
4. Black R8+1 (check, threatens mate next move, the only legal reply)
4. Black R8+1
5. Red K4+1
Why it works–
What to watch out for
Not forcing: the defender has 22 replies, so compare each one before playing it.
5. Black R8-9
5. Black R8-9
6. Red H6-5 (check)
6. Black K6+1
6. Black K6+1
7. Red R1+3 (check)
7. Black K6+1
7. Black K6+1
8. Red H5-4
Why it works–
What to watch out for
Not forcing: the defender has 23 replies, so compare each one before playing it.
8. Black P6=7
8. Black P6=7
9. Red R1-2
Why it works–
What to watch out for
Not forcing: the defender has 24 replies, so compare each one before playing it.
9. Black K6-1
9. Black K6-1
10. Red R1=4 (check, threatens mate next move, the only legal reply)
Why it works
Forcing: the opponent has only one reply, so the line cannot be avoided.
Creates an immediate mating threat that must be answered.
What to watch out forNo real drawback in this position.
10. Black K6=5
10. Black K6=5
11. Red H4+6 (check)
11. Black K5=4
11. Black K5=4
12. Red R4+2 (check)
12. Black K4+1
12. Black K4+1
13. Red R4-3
Why it works–
What to watch out for
Not forcing: the defender has 25 replies, so compare each one before playing it.
13. Black K4-1
13. Black K4-1
14. Red R4-2
Why it works–
What to watch out for
Not forcing: the defender has 25 replies, so compare each one before playing it.
14. Black R8=9
14. Black R8=9
15. Red R4=6
Why it works–
What to watch out for
Not forcing: the defender has 25 replies, so compare each one before playing it.
15. Black R9+8 (check)
15. Black R9+8
16. Red K4+1
Why it works–
What to watch out for
Not forcing: the defender has 21 replies, so compare each one before playing it.
16. Black R9=5
16. Black R9=5
17. Red H6-4 (check, threatens mate next move, the only legal reply)
Why it works
Forcing: the opponent has only one reply, so the line cannot be avoided.
Creates an immediate mating threat that must be answered.
What to watch out forNo real drawback in this position.
17. Black K4=5
17. Black K4=5
18. Red R6=5 (check)
Why it works–
What to watch out for
The Chariot stands where it can be captured.
18. Black K5=4
18. Black K5=4
19. Red R5-2 (captures the Chariot, sacrifices the Chariot)
Why it works
Wins material: takes the Chariot.
What to watch out for
Not forcing: the defender has 8 replies, so compare each one before playing it.
19. Black P4=5 (captures the Chariot)
19. Black P4=5
20. Red K4=5
Why it works–
What to watch out for
Not forcing: the defender has 8 replies, so compare each one before playing it.
20. Black P5=4
20. Black P5=4
21. Red H4-6
Why it works–
What to watch out for
Not forcing: the defender has 8 replies, so compare each one before playing it.
21. Black K4-1
21. Black K4-1
22. Red H6+5
Why it works–
What to watch out for
Not forcing: the defender has 7 replies, so compare each one before playing it.
22. Black K4=5
22. Black K4=5
23. Red K5=6
Why it works–
What to watch out for
Not forcing: the defender has 8 replies, so compare each one before playing it.
23. Black P4=5
23. Black P4=5
24. Red H5-6
Why it works–
What to watch out for
Not forcing: the defender has 9 replies, so compare each one before playing it.
24. Black P7=6
24. Black P7=6
25. Red H6+5
Why it works–
What to watch out for
Not forcing: the defender has 8 replies, so compare each one before playing it.
25. Black P6=5
25. Black P6=5
26. Red H5-3
Why it works–
What to watch out for
Not forcing: the defender has 8 replies, so compare each one before playing it.
26. Black -P+1 (threatens mate next move)
26. Black -P+1
27. Red H3+5
Why it works–
What to watch out for
Not forcing: the defender has 8 replies, so compare each one before playing it.
27. Black K5+1
27. Black K5+1
28. Red H5-4
Why it works–
What to watch out for
Not forcing: the defender has 9 replies, so compare each one before playing it.
28. Black K5+1
28. Black K5+1
29. Red H4+5
Why it works–
What to watch out for
Not forcing: the defender has 8 replies, so compare each one before playing it.
29. Black K5-1
29. Black K5-1
30. Red H5-4
Why it works–
What to watch out for
Not forcing: the defender has 9 replies, so compare each one before playing it.
30. Red H5-4

Variations and alternative defences

The source manual records 12 variations. Each branch starts from the move number shown.

Variation 1, from move 18: K5=6 19. R5=4 P7+1 20. H4-3+ K6=5 21. H3+4 R5-1+ 22. K4-1 R5=4 23. H4+3+ K5=4 24. H3-5+ K4=5 25. H5+7+ K5=4 26. H7+8+ Try it on the board
Variation 2, from move 22: R5=7 23. H4+6+ K5=4 24. H6+8+ Try it on the board
Variation 3, from move 19: K6=5 20. H4+3+ K5+1 21. R4+4+ K5-1 22. R4+1+ K5+1 23. H3+4 P7=6 24. R4=6+ K5=6 25. H4-2+ K6=5 26. H2-3+ Try it on the board
Variation 4, from move 17: 17. H6-8+ K4=5 18. H8+7+ K5+1 19. H7-6+ K5-1 20. R6=5+ K5=4 21. R5-2 P4=5 22. K4=5 P5=6 Try it on the board
Variation 5, from move 19: 19. R6=4 R5-1+ 20. K4-1 P4=5+ 21. K4-1 K5=4 22. R4+4+ R5-5 23. R4=5+ K4=5 24. H7-6+ K5-1 25. H6-8 P7+1 26. H8-6 P5=4 27. H6+5 K5-1 28. K4+1 P7+1 29. H5-6 K5+1 30. H6+5 Try it on the board
Variation 6, from move 25: 25. H6-5 P7+1 26. H5-7 P5=4 27. K4+1 P7=6 Try it on the board
Variation 7, from move 22: 22. H7+8 P7+1 23. R4+6 R5-6 24. R4-3 R5+5 25. R4+1+ R5-4 26. R4-1 R5=8 Try it on the board
Variation 8, from move 18: 18. R6=5+ K5=4 19. R5-2 P4=5 Try it on the board
Variation 9, from move 17: 17. H6-7+ K4=5 18. R6=5+ K5=4 19. R5-2 P4=5 20. K4=5 P5=6 Try it on the board
Variation 10, from move 16: P7=6 17. H6-8+ K4=5 18. H8+7+ K5+1 19. H7-6+ K5-1 20. R6=5+ K5=4 21. H6-4 R9-1+ 22. K4-1 R9-5 23. R5=4 K4=5 24. H4+5 R9=5 25. R4+3 K5-1 26. K4+1 P4=5 27. H5-6 K5+1 28. R4=5 R5+1 29. H6+5 Try it on the board
Variation 11, from move 21: R9=5 22. H4+5+ K4+1 23. R5=6+ K4=5 24. R6+6 K5-1 25. H5+3+ K5+1 26. R6=5+ K5=4 27. H3-5 R5=8 28. R5=7 K4=5 29. R7-2+ K5-1 30. H5+3+ K5=4 31. H3+4+ Try it on the board
Variation 12, from move 20: K5=6 21. H6-4 R9-1+ 22. K4-1 R9-3 23. R5=4 K6=5 24. H4+5 P4=5+ 25. K4=5 R9=5+ 26. K5=4 R5-1 Try it on the board

Final position

The record ends here.

Questions about this puzzle

Who moves first in "Probing the Subtle Depths"?

Red moves first, as in every puzzle of Chariot & Horse mates.

How many moves does the solution take?

30 moves. The main line is shown above; alternative defences are covered in the variations section.

What is the key move?

The first move R8=5 starts the combination. Everything that follows depends on it.

Can I play this position myself?

Yes. Open it on ChessZing, where the board checks your moves and shows the solution if you get stuck.

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