Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: annoying en passant x-ray

Author: Gerd Isenberg

Date: 15:28:19 11/30/03

Go up one level in this thread


On November 30, 2003 at 18:12:00, Bob Durrett wrote:

>On November 30, 2003 at 17:44:33, Gerd Isenberg wrote:
>
>>On November 30, 2003 at 17:36:10, Gerd Isenberg wrote:
>>
>>>On November 30, 2003 at 17:19:54, Georg v. Zimmermann wrote:
>>>
>>>>On November 30, 2003 at 17:18:19, Georg v. Zimmermann wrote:
>>>>
>>>>[d]8/8/8/8/3R1p1k/8/4P3/6K1 w - - 0 1
>>>>
>>>>Better i hope ..
>>>>
>>>>>
>>>>>white moves pawn, black can not capture en passant. wonderfull, breaks my new
>>>>>move generator.
>>>>>
>>>>>Uri, I think you are the expert on this. Ideas for workarounds ? :-)
>>>>>
>>>>>But the main reason I am posting is: are there any other situations like the
>>>>>above where I can with one move move 2 pieces out of the way of an x-ray attack
>>>>>?
>>>
>>>No, only ep.
>>>The conditions to deny ep capture generation are (iirr):
>>>
>>1.) The black pawn was pinned on the 4. rank before the white pawn push occured.
>>2.) The black pawn is pinned on the file.
>>3.) The black pawn is pinned on the other diagonal,
>>    the pawn intends to use for ep-capture.
>>4.) Discoverd check by the white pawn of course.
>>
>>Gerd
>>>
>>>
>>>
>>>>>
>>>>>Georg
>
>The rule I would follow is:  "You cannot play a move which puts your own king
>into check."  I hope that was built into all chess engines.
>
>Bob D.

Sure, but if you want to implement legal move generation,
to avoid making/unmaking invalid moves, you need some other conditions.
Ep is a bit annoying, all others are easier to implement.
Pinned piece determination is required, but also fine for other purposes.

Gerd



This page took 0.01 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.