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Subject: Re: Tough solution

Author: Vincent Lejeune

Date: 17:10:13 01/14/98

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On January 14, 1998 at 19:49:10, Stuart Cracraft wrote:

>On January 14, 1998 at 18:24:54, Vincent Lejeune wrote:
>
>>On January 14, 1998 at 18:07:45, Stuart Cracraft wrote:
>>
>>>On January 14, 1998 at 16:53:06, Vincent Lejeune wrote:
>>>
>>>>I've red a book chess problem, and find the following position :
>>>>
>>>>[Event "?"]
>>>>[Site "?"]
>>>>[Date "??.??.????"]
>>>>[Round "?"]
>>>>[White "W"]
>>>>[Black "B"]
>>>>[Result "*"]
>>>>[WhiteElo "?"]
>>>>[BlackElo "?"]
>>>>[FEN "8/7p/6pP/k4pP1/b1p1pP2/KpPpP3/1P1P4/7Q w - - 0 1"]
>>>>
>>>>
>>>>and the book say :
>>>>
>>>>If it's white to moves, black are in zugzwang because after :
>>>>1.Qd1 B moves 2.Qxc3 cxb3 3.Kxd3 , the 2 passed pawn win for white !!!
>>>>I don't understand everything in the position (and I don't blame who
>>>>don't understand like me ;)  ).
>>>>
>>>>I look for someone who can analyse this position with a strong chess
>>>>program...
>>>>
>>>
>>>Well, don't know about the "strong", but here's my program's analysis.
>>>
>>>K2 1/13/98 0.19
>>>Type ? for help.
>>>Transposition table:  Entries=100K Size=6400K
>>>Pawn transposition table:  Entries=31K Size=2000K
>>>? set time 60
>>>? test solve ../tests/testone.ci
>>>60 seconds per problem.
>>>lejeune
>>>Qd1
>>>
>>>white
>>>. . . . . . . .
>>>. . . . . . . p
>>>. . . . . . p P
>>>k . . . . p P .
>>>b . p . p P . .
>>>K p P p P . . .
>>>. P . P . . . .
>>>. . . . . . . Q
>>>
>>>Phase = Middlegame, Target search time = 60 sec, Root score = 442
>>> 1+    0.0    697         3      Qh4
>>> 1.    0.0    603        17      Qh4
>>> 2-    0.1    431        56      Qh4
>>> 2&    0.1    426        64      Qh4 Kb5
>>> 2&    0.1    427        78      Qc1 Kb5
>>> 2.    0.1    431        86      Qd1 Kb5
>>> 3+    0.1    697       161      Qd1
>>> 3.    0.1    603       202      Qd1 Kb5 Qa1
>>> 4-    0.1    446       266      Qd1
>>> 4.    0.1    446       311      Qd1 Kb5 Qe1 Ka5
>>> 5+    0.1    697       531      Qd1
>>> 5.    0.1    603       706      Qd1 Kb5 Qe1 Ka5 Qa1 Kb5
>>> 6-    0.1    431       915      Qd1
>>> 6&    0.1    430      1160      Qd1 Kb5 Qe1 Ka5 Qf1 Kb5
>>> 6.    0.1    430      1414      Qd1 Kb5 Qe1 Ka5 Qf1 Kb5 Qa1 Ka5 Qe1 Kb5
>>>Qa1
>>> 7&    0.2    430      1699      Qd1 Kb5 Qe1 Ka5 Qf1 Kb5 Qa1 Ka5 Qe1 Kb5
>>>Qa1
>>> 7.    0.2    430      1942      Qd1 Kb5 Qe1 Ka5 Qf1 Kb5 Qa1 Ka5 Qe1 Kb5
>>>Qa1
>>> 8&    0.2    434      2571      Qd1 Kb5 Qe1 Ka5 Qf1 Kb5 Qa1 Ka5 Qf1
>>> 8.    0.2    434      2884      Qd1 Kb5 Qe1 Ka5 Qf1 Kb5 Qa1 Ka5 Qf1
>>> 9&    0.2    434      3271      Qd1 Kb5 Qe1 Ka5 Qf1 Kb5 Qa1 Ka5 Qf1
>>> 9.    0.2    434      3688      Qd1 Kb5 Qe1 Ka5 Qf1 Kb5 Qa1 Ka5 Qf1
>>>10&    0.3    430      4817      Qd1 Kb5 Qe1 Ka5 Qf1 Kb5 Qa1 Ka5 Qe1 Kb5
>>>Qa1
>>>10.    0.4    430     11420      Qd1 Kb5 Qe1 Ka5 Qf1 Kb5 Qa1 Ka5 Qe1 Kb5
>>>Qa1
>>>11+    0.9    507     27335      Qd1
>>>11.    1.0    503     30122      Qd1 Kb5 Qf1 Ka5 Qh1 Kb5 Qa1 Ka5 Qh1
>>>12-    2.2    427     70920      Qd1
>>>12&    2.3    425     72688      Qd1 Bb5 Qa1 Ba6 Qf1 Kb5 Qe1 Ka5 Qa1 Kb5
>>>Qb1
>>>                                 Ka5 Qa1
>>>12.    2.3    425     72756      Qd1 Bb5 Qa1 Ba6 Qf1 Kb5 Qe1 Ka5 Qa1 Kb5
>>>Qb1
>>>                                 Ka5 Qa1
>>>13&    2.8    430     92382      Qd1 Bb5 Qa1 Be8 Qe1 Ba4 Qf1 Bb5 Qe1 Be8
>>>Qa1
>>>                                 Bd7 Qe1 Bb5 Qa1
>>>13.    2.9    430     98266      Qd1 Bb5 Qa1 Be8 Qe1 Ba4 Qf1 Bb5 Qe1 Be8
>>>Qa1
>>>                                 Bd7 Qe1 Bb5 Qa1
>>>14&    3.4    430    116144      Qd1 Bb5 Qa1 Be8 Qe1 Bb5 Qf1 Be8 Qa1 Bd7
>>>Qe1
>>>                                 Bb5 Qf1 Be8 Qa1 Bd7 Qe1 Bb5
>>>14.    6.6    430    214074      Qd1 Bb5 Qa1 Be8 Qe1 Bb5 Qf1 Be8 Qa1 Bd7
>>>Qe1
>>>                                 Bb5 Qf1 Be8 Qa1 Bd7 Qe1 Bb5
>>>15&    8.2    430    277129      Qd1 Bb5 Qa1 Be8 Qe1 Bb5 Qf1 Be8 Qa1 Bd7
>>>Qe1
>>>                                 Bb5 Qf1 Be8 Qa1 Bd7 Qe1 Be8 Qa1
>>>15.   19.7    430    710557      Qd1 Bb5 Qa1 Be8 Qe1 Bb5 Qf1 Be8 Qa1 Bd7
>>>Qe1
>>>                                 Bb5 Qf1 Be8 Qa1 Bd7 Qe1 Be8 Qa1
>>>16&   23.8    430    855943      Qd1 Bb5 Qa1 Ba4 Qh1 Be8 Qf1 Bd7 Qe1 Be8
>>>Qb1
>>>                                 Bb5 Qa1 Ba4 Qh1
>>>16.   41.3    430   1430961      Qd1 Bb5 Qa1 Ba4 Qh1 Be8 Qf1 Bd7 Qe1 Be8
>>>Qb1
>>>                                 Bb5 Qa1 Ba4 Qh1 Bb5 Qa1
>>>17&   49.1    430   1722280      Qd1 Bd7 Qa1 Ba4 Qb1 Bb5 Qe1 Bd7 Qa1 Ba4
>>>Qb1
>>>                                 Bb5
>>>17.   54.6    430   1930188      Qd1 Bd7 Qa1 Ba4 Qb1 Bb5 Qe1 Bd7 Qa1 Ba4
>>>Qb1
>>>                                 Bb5 Qa1 Be8 Qb1 Bb5
>>>18.   60.0    430   2144013      Qd1 Bd7 Qa1 Ba4 Qb1 Bb5 Qe1 Bd7 Qa1 Ba4
>>>Qb1
>>>                                 Bb5 Qa1 Be8 Qb1 Bb5
>>>
>>>My move is : Qd1
>>>Time = 60.0 Rate=35730 Nodes=[1536201/607812/2144013]
>>>Eval=431520 RptCnt=11112 NullCut=100569
>>>Extensions: Check=151557 Recapture=15205 Pawn=135 OneMove=0
>>>            Threat=0 DeepSearch=0 Mate=0
>>>Material=[1600/1000] Worst=[-1080/97]
>>>Hash: Success=26% Collision=66%
>>>Hash Counts: ReadHits=446157, ReadProbes=1658921, WriteColl=326019,
>>>WriteTries=493572
>>>Pawn Hash: Success=98% Collision=12%
>>>Pawn Counts: ReadHits=853541, ReadProbes=862338, WriteColl=1095,
>>>WriteTries=8797
>>>
>>>black
>>>. . . . . . . .
>>>. . . . . . . p
>>>. . . . . . p P
>>>k . . . . p P .
>>>b . p . p P . .
>>>K p P p P . . .
>>>. P . P . . . .
>>>. . . Q . . . .
>>>
>>>+++  Qd1 Qd1
>>>
>>>Correct so far: 1 Total problems: 1 Percent: 100%
>>>
>>>********* Grand totals **********
>>>Time = 60.0 Rate=35730 Nodes=[1536201/607812/2144013]
>>>EvalCnt=431520 RptCnt=11112 NullCut=100569
>>>Extensions: Check=151557 Recapture=15205 Pawn=135 OneMove=0
>>>            Threat=0 DeepSearch=0 Mate=0
>>>Hash: Success=26% Collision=66%
>>>Pawn Hash: Success=98% Collision=12%
>>
>>
>>So your program don't make any progress in the position !?
>
>Nothing that involves a queen sacrifice in 60 seconds.
>
>However, funny that you should send that. I am adding some
>passed pawn logic tonight and we'll see if that helps.
>
>--Stuart

It's a very hard positon to solve because :
1) You should see that no progress is possible until you sacrifice the
queen
2) You should see that the endgame with two passed pawns against the
bishop is win for white (that the book said, but it's the first thing to
verify)




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