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Subject: Re: To Bob Hyatt - Crafty question

Author: pavel

Date: 00:13:13 10/23/00

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On October 22, 2000 at 23:08:57, Robert Hyatt wrote:

>On October 22, 2000 at 17:43:15, Lenard Spencer wrote:
>
>>In evaluate.c, the trapped-bishop code has something that has me curious.
>>
>>>  if (WhiteBishops) {
>>>    if (WhiteBishops&mask_A7H7) {
>>>      if (WhiteBishops&SetMask(A7) && SetMask(B6)&BlackPawns)
>>>        score-=BISHOP_TRAPPED;
>>>      else if (WhiteBishops&SetMask(H7) && SetMask(G6)&BlackPawns)
>>>        score-=BISHOP_TRAPPED;
>>>    }
>>>  }
>>>  if (BlackBishops) {
>>>    if (BlackBishops&mask_A2H2) {
>>>      if (BlackBishops&SetMask(A2) && SetMask(B3)&WhitePawns)
>>>          score+=BISHOP_TRAPPED;
>>>      else if (BlackBishops&SetMask(H2) && SetMask(G3)&WhitePawns)
>>>        score+=BISHOP_TRAPPED;
>>>    }
>>>  }
>>
>>The way I see this, if someone were so foolish to trap BOTH his bishops,
>>wouldn't this only see one of them, skipping the second check after it finds the
>>first one?  Or is this just something to speed up the search a tiny bit upon
>>finding a trapped bishop at A2/A7?  Or am I missing something else?
>>
>>Thanks.
>>
>>BTW, I finally got the BOOK.BIN file, with (would you believe???) AOL's "Keyword
>>FTP".  All that after both IE and Netscape choked at the same point in the file.
>> Go figure....
>
>
>That is just "habit" programming.  99.999% of the time, both ifs are
>executed, since no bishops are hung.  When one is on the key square, then
>the other square is not checked...
>
>I doubt it matters at all how it is done.
>
>No idea what would hang an ftp connection, other than a very poor internet
>link that loses too many packets...

i think he is right, when you try to download book.bin file the browser executes
it in .txt format, as a result hangs (on slow connection). Better idea is to
have the books in zip file ;)


Pavel



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