Log Bridge Locks the Stream

"Log Bridge Locks the Stream" is a Xiangqi (Chinese Chess) puzzle from the collection Xinwu Endgame Collection. Red moves first and wins in 14 moves; the key first move is R3=4. Below you will find the full solution, what each move achieves, where it could go wrong, and the alternative defences.

Solve this puzzle on ChessZing →

Free, in the browser, no download.

Pieces on the board

Red has a General, 2 Chariots, 5 Soldiers. Black has a General, a Advisor, a Elephant, a Horse, a Cannon, 5 Soldiers.

Solution move by move

1. Red R3=4 (captures the Horse, check, sacrifices the Chariot)
Why it works
Wins material: takes the Horse.
What to watch out for
Gives up the Chariot; the follow-up must be exact or the sacrifice is wasted.
1. Black A5+6 (captures the Chariot)
1. Black A5+6
2. Red R5+2 (check, the only legal reply)
Why it works
Forcing: the opponent has only one reply, so the line cannot be avoided.
What to watch out forNo real drawback in this position.
2. Black K6+1
2. Black K6+1
3. Red P2=3 (threatens mate next move)
Why it works
Creates an immediate mating threat that must be answered.
What to watch out for
Not forcing: the defender has 19 replies, so compare each one before playing it.
3. Black +P+1 (check, threatens mate next move, the only legal reply)
3. Black +P+1
4. Red K5=4 (captures the Soldier, threatens mate next move)
Why it works
Wins material: takes the Soldier.
Creates an immediate mating threat that must be answered.
What to watch out for
Not forcing: the defender has 17 replies, so compare each one before playing it.
4. Black A6-5
4. Black A6-5
5. Red P3+1 (captures the Cannon, 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.
Wins material: takes the Cannon.
Creates an immediate mating threat that must be answered.
What to watch out forNo real drawback in this position.
5. Black K6+1
5. Black K6+1
6. Red P6=5 (check, sacrifices the Soldier, 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 for
Gives up the Soldier; the follow-up must be exact or the sacrifice is wasted.
6. Black K6=5 (captures the Soldier)
6. Black K6=5
7. 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.
7. Black P4=5 (threatens mate next move)
7. Black P4=5
8. Red R1-2 (captures the Elephant, check, threatens mate next move, the only legal reply, the General has no escape square)
Why it works
Forcing: the opponent has only one reply, so the line cannot be avoided.
Wins material: takes the Elephant.
Creates an immediate mating threat that must be answered.
Takes away the General's escape squares.
What to watch out forNo real drawback in this position.
8. Black A5+6 (threatens mate next move)
8. Black A5+6
9. Red P7=6 (check)
Why it works–
What to watch out for
The Soldier stands where it can be captured.
9. Black K5-1 (threatens mate next move)
9. Black K5-1
10. Red P3=4 (check, sacrifices the Soldier)
Why it works–
What to watch out for
Gives up the Soldier; the follow-up must be exact or the sacrifice is wasted.
10. Black K5=6 (captures the Soldier, threatens mate next move)
10. Black K5=6
11. Red R1+1 (check, the only legal reply)
Why it works
Forcing: the opponent has only one reply, so the line cannot be avoided.
What to watch out forNo real drawback in this position.
11. Black K6-1 (threatens mate next move)
11. Black K6-1
12. Red R1-7
Why it works–
What to watch out for
Not forcing: the defender has 14 replies, so compare each one before playing it.
12. Black P6+1 (check, the only legal reply, the General has no escape square)
12. Black P6+1
13. Red R1=4 (captures the Soldier, sacrifices the Chariot)
Why it works
Wins material: takes the Soldier.
What to watch out for
Gives up the Chariot; the follow-up must be exact or the sacrifice is wasted.
Not forcing: the defender has 10 replies, so compare each one before playing it.
13. Black P5=6 (captures the Chariot, check)
13. Black P5=6
14. Red K4+1 (captures the Soldier)
Why it works
Wins material: takes the Soldier.
What to watch out for
Not forcing: the defender has 7 replies, so compare each one before playing it.
14. Black P7=6
14. Black P7=6

Variations and alternative defences

What if Black defends differently? The alternatives below were checked with the rules engine; lines marked with a mating move lose at once, the others are worth trying on the analysis board.

1. Black A5+6
- If Black plays C7=6 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays K6=5 instead: no immediate mate; the attack continues. Try it on the board
3. Black +P+1
- If Black plays P2=3 instead: Red mates immediately with P3+1. Try it on the board
- If Black plays P2=1 instead: Red mates immediately with P3+1. Try it on the board
- If Black plays P4+1 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P4=5 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P4=3 instead: Red mates immediately with P3+1. Try it on the board
- If Black plays +P=7 instead: Red mates immediately with P3+1. Try it on the board
4. Black A6-5
- If Black plays P2=3 instead: Red mates immediately with P3+1. Try it on the board
- If Black plays P2=1 instead: Red mates immediately with P3+1. Try it on the board
- If Black plays P4+1 instead: Red mates immediately with P3+1. Try it on the board
- If Black plays P4=5 instead: Red mates immediately with P3+1. Try it on the board
- If Black plays P4=3 instead: Red mates immediately with P3+1. Try it on the board
- If Black plays P6+1 instead: no immediate mate; the attack continues. Try it on the board
7. Black P4=5
- If Black plays P2=3 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P2=1 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P4+1 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P4=3 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P6+1 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P6=7 instead: no immediate mate; the attack continues. Try it on the board
9. Black K5-1
- If Black plays K5=4 instead: no immediate mate; the attack continues. Try it on the board
10. Black K5=6
- If Black plays K5-1 instead: Red mates immediately with R1+2. Try it on the board
12. Black P6+1
- If Black plays P2=3 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P2=1 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P5+1 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P5=6 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P5=4 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P6=7 instead: no immediate mate; the attack continues. Try it on the board
13. Black P5=6
- If Black plays P2=3 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P2=1 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P5+1 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P5=4 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P7+1 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P7=8 instead: no immediate mate; the attack continues. Try it on the board
14. Black P7=6
- If Black plays P2=3 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P2=1 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P7+1 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays P7=8 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays K6=5 instead: no immediate mate; the attack continues. Try it on the board
- If Black plays K6+1 instead: no immediate mate; the attack continues. Try it on the board

Final position

The record ends here.

Questions about this puzzle

Who moves first in "Log Bridge Locks the Stream"?

Red moves first, as in every puzzle of Xinwu Endgame Collection.

How many moves does the solution take?

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

What is the key move?

The first move R3=4 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.

← Previous puzzle: Quenching Thirst by Gazing at Plums Next puzzle: Oriole Darting Through Willow Leaves →

Nearby puzzles

Shuttling Through the Moon
29 moves
Gazing at the Clouds, Stamping One's Feet
11 moves
Quenching Thirst by Gazing at Plums
22 moves
Oriole Darting Through Willow Leaves
25 moves
Lost on the Way to Peach Blossom Spring
18 moves
Pink Peach, Green Willow
10 moves