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Pao. Moves like rook, but must jump when taking.[All Comments] [Add Comment or Rating]

David Cannon wrote on Fri, Apr 18, 2003 11:26 AM UTC:Excellent ★★★★★

The movement of the Cannon is one of three significant differences between
Xiangqi (Chinese Chess) and Changgi (Korean Chess) [the other differences
concern the Elephant and the design of the board - Changgi has no river).

The Koreans have somewhat simplified the movement of the Cannon.  Unlike
its Chinese cousin, the Korean cannon moves as it captures : it cannot
move at all without flying over a 'screen' piece.

The effect of all this is that the Korean cannon tends to be an immensely
powerful piece in the early and mid-stages of the game, equal or superior
to the CHA (rook), but practically useless in the endgame, when there are
few pieces left to leap over.  Part of the strategy of Changgi is knowing
just when to exchange the Cannon for another piece.

Another distinctively Korean feature of the Cannon is that, unlike its
Chinese counterpart, it cannot capture an enemy cannon, or leap over a
fellow-cannon, friend or foe.  Shades of blood brothers?

David Paulowich wrote on Mon, Apr 3, 2006 03:07 PM UTC:Excellent ★★★★★

The longest possible forced mate with King and two Knights against a lone King on the standard 8x8 board is exactly one move long (the result of a blunder). Consider the following endgame. White: King b3, Cannon d3, Cannon d4, Black: King b1, with the moves 1.Cd3-f3 Kb1-a1?? 2.Cf3-f1 Ka1-b1 3.Cd4-d1 mate. Black's first move leads to a forced mate in two moves here, but there is no hope for a win if Black does not blunder.

And now for some good news. After playtesting Mir Chess, I have concluded that King and Cannon and Knight are strong enough to force a lone King into the corner and checkmate him.

Joost Brugh wrote on Mon, Apr 3, 2006 05:14 PM UTC:

For two Camels, two Knights or a Wildebeest we can prove that the longest
forced mate is one move, because the geometry allows only a few mating
patterns. This two-move example with two cannons is not trivial. Is it
possible to prove that two moves is the maximum. Known is that the mating
patterns is always with the Black King on the side (X1), White's King on
X3 or on b3 against when X = a. And White's cannons are at Y1 and Z1 with
Y between X and Z and Y not adjacent to Z. The last move is a vertical move
by a cannon (C YA-Y1 or C ZA-Z1). Blacks last move is a horizontal King
move, which can only be forced if the end file is involved (Second rank
squares can only be covered by the White King), so this must be Ka1-b1,
which means that X = b. One retromove by a cannon later, c1 must be
covered. This is impossible. With two (Cannon + passive Bishop)-pieces
(passive Bishop is a Bishop that does not capture), it should work (from:
White CmB on c4 and c5, White King King b3, Black King b1, Black to move)
1. ...,Kb1-a1 2. CmB c4-f1, Ka1-b1 3. CmB c5-g1#. Probably (not certainly,
it should be possible to force this with two CmB's and a King against a
lone King.

It would be interesting to prove this (and of course the
King+Cannon+Knight against King)

David Paulowich wrote on Mon, Apr 3, 2006 06:35 PM UTC:

The position White: King b4, Cannon b6, Ferz c3 and Black: King a2 leads to 1.Cc6 Ka1 2.Kb3 Kb1 3.Fe2 Ka1 4.Ch6 Kb1 5.Ch1 Ka1 Fe1 mate. Note that 5.Fe1 Kc1 6.Ch1 also mates.

I am not sure if King and Cannon and Alfil can force mate. Starting with White: King b4, Cannon b6, Alfil c5 and Black: King a2, how can we force the Black King back to the first rank, allowing the White King to move to b3? Note that the White Alfil cannot attack any square on the second rank.

H. G. Muller wrote on Fri, Oct 17, 2008 10:55 AM UTC:

I have been play-testing the Cannon in a Chess context, and it seems its opening value is about equal,
perhaps slightly less than that of a Knight. When I replace two Knight by two Cannons in the FIDE array,
the Knights win about 52%, which is barey significant. (Giving Pawn odds would result in a 68% victory.)
Replacing the Bishops by Cannons leads to a 58% victory for the Bishops (over a 400-game match),
which is approximately what the Bishop pair wins over two Knights.

Using the Kaufman value N=325 (centiPawn), this means that Cannon = 320. This makes it appreciably
stronger than the other well-known hopper, the Grasshopper, which has a value of 175 cP.

You are right about the mating potential of C+N and C+F. I adapted my tablebase generator to handle
a Cannon. The mate with C+F apparently can only be enforced in te corner of the Ferz color,
and it migt take 59 moves to drive the bare King there. Cannon + Wazir is also a general win,
and goes slightly faster, as the mate can be performed in any corner (41 moves max).
Cannon+Knight is easy by comparizon: only 30 moves. With Cannon+Alfil it is almost always draw.
There are some mating sequences, though (0.5% with wtm, 0.1% btm). The longest takes 13 moves:
White: Kd6, Cc5, Aa7; black: Ka1 (wtm).

Staunton-style Cannon

Anonymous wrote on Thu, May 13, 2010 07:32 AM UTC:

You have to read Changi rules more carefull: there are much more differences between XQ and Changi! These are moves af guards, pawns, palace diagonal lines, opening position and stalemate rules!

KelvinFox wrote on Wed, Mar 6, 2019 01:05 PM UTC:

Someone on wikipedia added the name Nao for a piece that moves like the Nightrider version of the Cannon. Does anyone know if this name actually was sourced from a chess variants book or was made up?