The Chess Variant Pages



What is wrong with Shou Dou Qi?

by Panther!

Shou Dou Qi is a Chinese children's game described by Hans Bodlaender in his fantastic online book on chess variants.

His description of Shou Dou Qi is based on E. Glonnegger's "Das Spielebuch" and R.C. Bell's "Board and Table Games from many Civilizations". Both authors are extremely unreliable and their books should, if possible, NOT be used as the only source of a game.

I used the following source:

Rainer Schmidt. Das spielt das Volk in China. China Studien- und Verlagsgesellschaft, Frankfurt am Main1981.

According to another book Rainer Schmidt was the founder and the first president of the German Xiang Qi Association.

Schmidt's rules of Shou Dou Qi were reviewed by Professor Dr. Yu Chen-Lie before publication. For that reason alone my source can be considered sufficiently reliable.

Bodlaender's rules of Shou Dou Qi are essentially correct, however, some of his comments show that he is uncertain about this pleasant fact.

Bodlaender mentions an observation of Jeff Mallet that appears to be rather superficial.

Bodlaender states:

" A piece of a player in one of his own trap squares cannot be taken by the opponent. Pieces in a trap square of the opponent are very weak: they can be taken by any other piece when in such a trap square. ., this rule is probably wrong: one should just have fill each of ones traps by a piece and the opponent can never reach the den."

(The current version of the description in the original webpage has a slightly different comment. Note added by HB.)

My critique:

(1)

It should be noted that many old "ethno-" games and, probably, even more modern "capitalist" games have rules which allow an easy drawing strategy. Examples are Abalone, Outwit, Jumpin, Chessball, Rondo, early Halma and Shou Dou Qi! This doesn't mean that the rules are wrong, it means that the authors made a stupid mistake or that the games were not meant to be played by truly intelligent people.

Some classic games have extremely difficult drawing startegies such as Nine Men's Morris (not really proved because Ralf Gasser didn't use the official rules of the World Morris Federation) or Teeko (i don't know if the advanced tournament rules were used when the game was "solved"). However, both games are rather difficult to draw and no human player has been able to reproduce these drawing strategies in actual play. In the worst case (champion level of play) about 50% of Morris games ends in a draw and less than 5% of Teeko games.

(2)

It is not true that when you have filled each of your traps with a piece the opponent can never reach the den. Your opponent needs only to capture all your other pieces. Then one of your pieces would have to leave your trap and could be captured.. Note: You must move in Shou Dou Qi ("Zugzwang"!).

Nevertheless, Mallet's idea pointed into the right direction.

You can draw Shou Dou Qi by

  1. moving your elephant to your central trap
    -- while --
  2. occupying the other two traps with any other pieces (except your rat)
    -- and --
  3. moving your rat onto a water square.
You must do all these three things!

Only then it doesn't matter what your opponent is doing. Always, you will EITHER be able to move your elephant forth from and back to your central trap OR your rat inside the lake WITHOUT jeopardizing them. Your opponent cannot threaten to capture both, your elephant and your rat, at the same time.

In other words:

If you want to capture an elephant which is moving from a central trap because of Zugzwang you need an elephant and a rat on the squares diagonally in front of him. If you want to capture a rat which is in a lake (again: because of Zugzwang) you need your rat to chase it away. If you want to do both, you need two rats. You only have one rat. Therefore you cannot do both.

For that reason Shou Dou Qi is indeed a draw. But it is much more complicated than claimed by Mallet and Bodlaender.

Panther

Written by Ralf "Panther" Gering. Webpage posted by Hans Bodlaender.
WWW page created: April 9, 2001. Last modified: April 12, 2001.