Author: John Merlino
Date: 12:02:57 04/24/02
Go up one level in this thread
On April 24, 2002 at 14:55:57, Roy Eassa wrote:
>On April 24, 2002 at 14:03:30, John Merlino wrote:
>
>>On April 24, 2002 at 13:48:12, Roy Eassa wrote:
>>
>>>
>>>Does ANY program see the whole line (3 underpromotions) up front?
>>>
>>>[d] 1b6/4P3/1P2PN2/8/8/P1k5/P1p2P2/K5B1 w - - 0 1
>>>
>>>1.Ne4+
>>>
>>> [1.Nd5+? Kd2 2.Kb2 c1Q+ 3.Kb3 Bd6! 4.Nb4 Bxe7 5.b7 Qc7 -+]
>>>
>>>1...Kd3 2.Nc5+
>>>
>>> [2.Kb2? Be5+ and Black mates]
>>>
>>>2...Kc3 3.Nb3 Be5 4.f4! forced
>>>
>>> [4.Bh2? Bf6 5.e8N Bh8 and Black mates!]
>>>
>>>4...Bf6 {or ...Bg7} 5.e8N! forced
>>>
>>>5...Bh8 6.f5! forced
>>>
>>>6...Be5 7.Bh2! forced
>>>
>>>7...Bxh2 8.b7! forced
>>>
>>>8...Be5! 9.b8B!
>>>
>>> [9.b8Q? Kc4+ 10.Qxe5 c1Q+ 11.Nxc1 stalemate]
>>>
>>>9...Bxb8 10.Nc7! forced
>>>
>>>10...Bxc7 11.e7 forced
>>>
>>>11...Be5 12.e8R!
>>>
>>> [12.e8Q? Kc4+ 13.Qxe5 c1Q+ 14.Nxc1 stalemate]
>>>
>>>12...Bg7 {or ...Bf6}
>>>
>>>13.Re6 followed by f6
>>>
>>>
>>>Problem attributed to Mark Libiurkin, circa 1933.
>>
>>There is a problem with the above line. Here is CM's analysis from the initial
>>position (note the first seven moves agree with your above line):
>>
>>Time Depth Score Positions Moves
>>0:00 2/3 9.94 3081 1.Ne4+ Kd3 2.Nc5+ Kc3 3.Nb3 Kc4
>> 4.Kb2
>>0:00 3/4 7.65 6474 1.Ne4+ Kd3 2.Nc5+ Kd2 3.Nb3+ Kd1
>> 4.f4 Bxf4 5.Bd4
>>0:00 4/5 9.82 13420 1.Ne4+ Kd3 2.Nc5+ Ke2 3.Kb2 Kd1
>> 4.Nd3 Be5+ 5.Kb3
>>0:00 5/6 12.01 27685 1.Ne4+ Kd3 2.Nc5+ Kd2 3.Nb3+ Kd1
>> 4.f4 Bxf4 5.Bd4 Be3 6.Bxe3
>>0:00 6/7 12.07 55694 1.Ne4+ Kd3 2.Nc5+ Kc3 3.Nb3 Be5
>> 4.Bh2 Bf6 5.e8=N Be7 6.Be5+ Kc4
>>0:01 7/8 12.01 105397 1.Ne4+ Kd3 2.Nc5+ Kc3 3.Nb3 Be5
>> 4.f4 Bf6 5.e8=N Bh8 6.f5
>>0:02 8/9 12.23 199081 1.Ne4+ Kd3 2.Nc5+ Kc3 3.Nb3 Be5
>> 4.f4 Bf6 5.e8=N Bh8 6.f5 Be5 7.f6
>>0:05 9/10 9.27 469863 1.Ne4+ Kd3 2.Nc5+ Kc3 3.Nb3 Be5
>> 4.f4 Bf6 5.e8=N Bh8 6.f5 Be5 7.Bd4+
>> Bxd4
>>0:09 10/11 9.37 865339 1.Ne4+ Kd3 2.Nc5+ Kc3 3.Nb3 Be5
>> 4.f4 Bf6 5.e8=N Bh8 6.f5 Be5 7.Bh2
>> Bxh2 8.Nf6
>>0:21 11/12 9.37 1872831 1.Ne4+ Kd3 2.Nc5+ Kc3 3.Nb3 Be5
>> 4.f4 Bf6 5.e8=N Bh8 6.f5 Be5 7.Bh2
>> Bxh2 8.Nf6
>>
>>However, in your line, 8...Be5 loses outright. Here is Chessmaster 9000's
>>analysis after 8.b7, which says that 8...Kd3 is the best move, and leads to a
>>game where White has a queen and three pawns, and Black has a queen and a
>>bishop:
>>
>>Time Depth Score Positions Moves
>>0:00 2/3 7.65 917 8...Be5 9.b8=Q Bxb8
>>0:00 3/4 7.61 2731 8...Be5 9.b8=B Bxb8 10.f6
>>0:00 4/5 7.73 7396 8...Be5 9.b8=B Bxb8 10.f6 Bf4
>>0:00 4/5 6.00 9191 8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
>> 11.Kb3 Kxc1 12.Nf6
>>0:00 5/6 5.44 12675 8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
>> 11.Kb3 Kxc1 12.Nf6 Kd2
>>0:00 6/7 4.47 21350 8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
>> 11.Kb3 Kxc1 12.f6 Kb1 13.f7 c1=Q
>> 14.f8=Q Qc3+ 15.Ka4 Kxa2
>>0:00 7/8 3.61 40916 8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
>> 11.Kb3 Kxc1 12.Nf6 Kb1 13.b8=Q Bxb8
>>0:00 8/9 2.92 71437 8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
>> 11.Kb3 Kxc1 12.b8=Q Bxb8 13.f6
>> Kb1 14.f7 c1=Q 15.f8=Q Qc2+ 16.Kb4
>> Kxa2
>>0:01 9/10 2.91 129596 8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
>> 11.Kb3 Kxc1 12.f6 Kb1 13.f7 c1=Q
>> 14.f8=Q Qc3+ 15.Ka4 Qc6+ 16.Kb4
>> Qxb7+ 17.Kc5 Kxa2
>>0:03 10/11 2.62 316378 8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
>> 11.Kb3 Kxc1 12.Nc7 Bxc7 13.b8=Q
>> Bxb8 14.e7 Kd1 15.e8=Q c1=Q 16.Qxb8
>> Qc2+ 17.Kb4 Qxf5
>>0:07 11/12 2.28 637636 8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
>> 11.Kb3 Kxc1 12.Nc7 Bxc7 13.e7 Kb1
>> 14.e8=Q c1=Q 15.Qe2 Ka1 16.Qg2
>> Qb1+ 17.Kc3
>>0:15 12/13 2.27 1366434 8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
>> 11.Kb3 Kxc1 12.Nc7 Bxc7 13.e7 Kb1
>> 14.e8=Q c1=Q 15.Qe4+ Ka1 16.Qd4+
>> Kb1 17.Qd3+ Ka1 18.Qc3+ Qxc3+ 19.Kxc3
>> Kxa2 20.a4 Ka3
>>0:42 13/14 2.35 3685053 8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
>> 11.Kb3 Kxc1 12.Nc7 Bxc7 13.e7 Kd2
>> 14.e8=Q c1=Q 15.Qd7+ Ke3 16.Qd5
>> Kf4 17.f6 Qe3+ 18.Kc4 Qc1+ 19.Kb5
>> Qxa3
>>1:57 14/15 2.40 10277553 8...Kd3 9.Nc1+ Kd2 10.Kb2 Be5+
>> 11.Kb3 Kxc1 12.Nc7 Bxc7 13.e7 Kd2
>> 14.e8=Q c1=Q 15.Qd7+ Ke3 16.Qd5
>> Kf4 17.f6 Qe3+ 18.Kc4 Qxa3 19.Qd2+
>> Kf3
>>
>>Here is the analysis after 8...Be5 (note the remaining two underpromotions and
>>the much higher eval for White):
>>
>>Time Depth Score Positions Moves
>>0:00 2/3 0.00 453 9.b8=Q Kc4+ 10.Qxe5 c1=Q+ 11.Nxc1
>>0:00 2/3 7.61 680 9.b8=B Bxb8 10.f6
>>0:00 3/4 7.73 1862 9.b8=B Bxb8 10.f6 Bf4
>>0:00 4/5 7.47 5160 9.b8=B Bxb8 10.Nf6 Be5 11.Nd7
>>0:00 5/6 7.92 9869 9.b8=B Bxb8 10.Nc7 Kc4 11.e7 Ba7
>> 12.Kb2
>>0:00 6/7 10.09 16706 9.b8=B Bxb8 10.Nc7 Kc4 11.e7 Ba7
>> 12.Kb2 c1=Q+ 13.Kxc1
>>0:00 7/8 6.96 31443 9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
>> 12.e8=R Bg7 13.Re7
>>0:00 8/9 7.32 47963 9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
>> 12.e8=R Bg7 13.Rg8 Bf6
>>0:00 9/10 7.73 82525 9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
>> 12.e8=R Bf6 13.Re6 Bg7 14.Rc6+
>> Kd3+ 15.f6
>>0:01 10/11 7.82 147748 9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
>> 12.e8=R Bg7 13.Re6 Kd3+ 14.f6 Bf8
>> 15.Kb2
>>0:02 11/12 8.16 271525 9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
>> 12.e8=R Bg7 13.Re6 Kc4+ 14.f6 Bh8
>> 15.Kb2 Kd5 16.Re8 c1=Q+ 17.Kxc1
>> Bxf6
>>0:04 12/13 8.20 479706 9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
>> 12.e8=R Bg7 13.Re6 Kc4+ 14.f6 Bh8
>> 15.Rd6 Kb5 16.Kb2
>>0:09 13/14 8.44 924526 9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
>> 12.e8=R Bg7 13.Re6 Kc4+ 14.f6 Bh8
>> 15.Rd6 Kc3 16.Rc6+ Kd3 17.Kb2
>>0:19 14/15 9.24 1948702 9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
>> 12.e8=R Bg7 13.Re6 c1=Q+ 14.Nxc1
>> Kc2+ 15.f6 Bxf6+ 16.Rxf6 Kxc1 17.a4
>> Kc2 18.a5 Kd2 19.Kb2 Kd3 20.a6
>>0:53 15/16 9.80 5290251 9.b8=B Bxb8 10.Nc7 Bxc7 11.e7 Be5
>> 12.e8=R Bg7 13.Re6 Bf8 14.Rc6+
>> Kd3 15.Kb2 Ke4 16.f6 Ke5 17.f7
>> c1=Q+ 18.Rxc1
>>
>>jm
>
>
>Nothing to disagree with except the word "problem" -- White wins in all
>variations, but the main line I chose is the one where White is forced to
>underpromote three separate times (to a knight, bishop, and rook). The other
>line may evaluate less badly for Black, but it's a more straightforward win for
>a human IMHO.
>
>To my analysis above, I should have added the following variation to Black's
>8...Be5:
>
> [8...Kd3 9.b8Q Bxb8 10.Nc7 Bxc7 11.Nc1+ Kd2 12.Kb2 Be5+ 13.Kb3 Kxc1
> (13...Bf6 14.Ne2 +-)
> 14.e7 +-]
I agree with everything, except that you probably cannot expect a prog to find
this triple-underpromotion line, because Black has a better response than the
one that will force White to follow it.
jm
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