| Author |
Message |
Alfred Pfeiffer (Apf)
New member
Username: Apf
Post Number: 11
Registered: 7-2000
| | Posted on Monday, June 18, 2007 - 6:52 am: | |
For the game "Dama" aka "Turkish Checkers" aka "Turkish Draughts"
there exist some ZRF programs at the Zillions web site, e.g.:
a) "Checkers.zrf" (variant "Turkish Checkers") from the ZoG 2.0 distribution;
b) "Checker Games.zrf" (variant "Turkish Draughts") by Uwe Wiedemann;
c) "TurkishDraughts.zrf" by Jeremy Deane;
d) "KosovA Chess" (variant "KosovAs Chess") by Aepasa;
e) "Türkiye Chess.zrf" (variant "Turkish Chess") by Aepasa;
f) "Turkish Chess.zrf" (variant "Turkish Chess") by Aepasa.
But none of this program/variants does work correctly.
In the following I describe the details of the bugs in the zrf
for the variant "Turkish Checkers" from the "Checkers.zrf":
1) An obsolete part in the loss-conditions:
| ...
| (loss-condition (Red Black)
| (and (pieces-remaining 1 Checker)
| (pieces-remaining 0 King)
| (not (total-piece-count 0 King))
| )
| )
2) The rules allow the Kings 180° turns in multiple jumps.
This is forbidden.
3) When a Checker (unpromoted piece) captures to the
promotion-zone it always becomes a King and the move
terminates. But there are rare cases, where the Checker
in the promotion-zone could continue to jump (unpromoted!),
so the rules should test this, because series of captures
have to be done until to their ends.
4) In some mysteriouse cases the "maximal capture" condition
will not be fullfilled. This bug seems not to result from
an error in the zrf but in the Zillions engine itself. An example:
Black to move in the following position:
Black Checkers at a2, b3, c2, c3, c4, e2, g2;
Red Checkers at c5, c6.
After 1. c3-d3 the wrong answer is 1... c5xc3xa3xa1
The correct answer should be: 1... c5xc3xe3xg3xg1
I made a new ZRF ("Dama-rules.zrf") that avoids the bugs 1 to 3,
and by a stroke of good fortune I also found a version of it
where the bug 4 seems not to occur further.
I will submit it to ZoG for public at the next weekend.
Alfred Pfeiffer |
M Winther (Kalroten)
New member
Username: Kalroten
Post Number: 29
Registered: 1-2007
| | Posted on Monday, June 18, 2007 - 11:52 pm: | |
International Checkers and Frisian Checkers in the ZoG 2.0 distribution are also faulty. There exists a correct International Checkers on the ZoG site (Dama.zrf(?)). I created a functioning version of Frisian Checkers here:
http://hem.passagen.se/melki9/frisian.htm
/Mats |
M Winther (Kalroten)
New member
Username: Kalroten
Post Number: 30
Registered: 1-2007
| | Posted on Sunday, June 24, 2007 - 11:56 pm: | |
Alfred, it seems like you have forgotten to explain the rules of Turkish Checkers in the zrf. Otherwise it's an impressive piece of work.
/Mats |
Alfred Pfeiffer (Apf)
New member
Username: Apf
Post Number: 12
Registered: 7-2000
| | Posted on Tuesday, June 26, 2007 - 4:14 am: | |
Thank you. Indeed, in the "Dama.zrf" I forgot it.
I will correct it soon.
In the "Dama-collection.zrf" there is also a variant
"Play Dama (Turkish Checkers)".
It contains the rules. So meanwhile you could look there please.
Alfred Pfeiffer |
|