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Subject: Re: Ply depths?

Author: Miguel A. Ballicora

Date: 09:00:02 03/06/02

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On March 06, 2002 at 11:01:26, John Merlino wrote:

>On March 06, 2002 at 03:20:11, Uri Blass wrote:
>
>>On March 05, 2002 at 21:16:51, Steve wrote:
>>
>>>On March 05, 2002 at 00:10:46, John Merlino wrote:
>>>
>>>>On March 04, 2002 at 22:25:28, Sally Weltrop wrote:
>>>>
>>>>>On March 04, 2002 at 22:23:28, Sally Weltrop wrote:
>>>>>
>>>>>>[D]6k1/6pp/2qb4/8/2pQrNN1/1p3RPP/5P1K/r1B5 w - - 0 36
>>>>>>
>>>>>>of course 36)Qxa1 and Black resigns next move!
>>>>>
>>>>>
>>>>>this is taken from the 9th rd of Linares 2002
>>>>>
>>>>>Shirov,A (2715) - Ivanchuk,V (2717) [C88]
>>>>>Linares SuperGM Linares (9), 04.03.2002
>>>>>
>>>>>1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0-0 Be7 6.Re1 b5 7.Bb3 0-0 8.a4 Bb7 9.d3
>>>>>Re8 10.Nbd2 Bf8 11.c3 Na5 12.Ba2 c5 13.d4 d6 14.b4 exd4 15.bxa5 dxc3 16.Nf1 Nxe4
>>>>>17.axb5 axb5 18.a6 Bc6 19.Rxe4 Bxe4 20.Bxf7+ Kxf7 21.Ng5+ Kg8 22.Nxe4 Qc8
>>>>>23.Nxc3 Rxa6 24.Rb1 b4 25.Nd5 Ra7 26.Rb3 Ra1 27.h3 Re5 28.Nf4 Qe8 29.Rf3 c4
>>>>>30.Kh2 b3 31.Qd2 d5 32.Ne3 Bd6 33.g3 Qc6 34.Ng4 d4 35.Qxd4 Re4 36.Qxa1 1-0
>>>>
>>>>Two blunders in a row! (perhaps a victim of time pressure heading towards time
>>>>control?)
>>>>
>>>>After 34.Ng4, Ivanchuk is clearly in the lead:
>>>>
>>>>Time	Depth	Score	Positions	Moves
>>>>0:00	1/3	-1.86	1524		34...Rf5 35.Qc3 Ra2 36.Ne6
>>>>0:00	1/4	-2.47	6025		34...Rf5 35.Qc3 Ra2 36.Rd3 Rc2
>>>>0:00	2/5	-2.31	21581		34...Rf5 35.Bb2 Ra2 36.Ne3 Rxf4
>>>>					37.gxf4
>>>>0:00	2/6	-1.98	64702		34...Rf5 35.Qc3 Ra7 36.Bb2 Bxf4
>>>>					37.Rxf4 Rxf4 38.gxf4
>>>>0:02	3/7	-1.90	217927		34...Rf5 35.Qc3 Ra7 36.Ne6 Rxf3
>>>>					37.Qxf3 Bb4 38.Nd4 Qd6
>>>>0:08	3/8	-1.47	707718		34...Rf5 35.Qc3 Ra7 36.Ne6 Rxf3
>>>>					37.Qxf3 h5 38.Nd4 Qc5
>>>>0:40	4/9	-1.49	3345172		34...Rf5 35.Qc3 Ra7 36.Ne3 Be5
>>>>					37.Qb4 Rff7 38.Nexd5 Bxf4 39.Nxf4
>>>>					Qxf3 40.Qb8+ Rf8 41.Qxa7
>>>>2:45	4/10	-1.51	14440411	34...Rf5 35.Qc3 Ra7 36.Ne6 Rxf3
>>>>					37.Qxf3 h5 38.Ne5 Bxe5 39.Qf8+
>>>>					Kh7 40.Qf5+ g6 41.Qxe5
>>>>
>>>>But when the game is over....
>>>>
>>>>Time	Depth	Score	Positions	Moves
>>>>0:00	1/3	3.38	3069		36...Re1 37.Nh5 Qb7 38.Ne3
>>>>0:00	1/4	3.50	10479		36...Re1 37.Nh5 Qb7 38.Qa5 Qxf3
>>>>					39.Qxe1
>>>>0:00	2/5	3.28	34108		36...Re1 37.Nh5 Qb7 38.Kg2 Bb4
>>>>					39.Qb2
>>>>0:01	2/6	5.73	116307		36...Re1 37.Qxg7+ Kxg7 38.Nh5+
>>>>					Kh8 39.Bb2+ c3 40.Bxc3+ Qxc3 41.Rxc3
>>>>					Re8 42.Rxb3 Re2
>>>>0:01	2/6	4.06	165811		36...Re7 37.Kg2 Re1 38.Nh5 Bf8
>>>>					39.Qc3 Qe6 40.Ne3
>>>>0:02	2/6	3.96	190722		36...Rxf4 37.Rxf4 Bxf4 38.Bxf4
>>>>					c3 39.Ne5 Qc5 40.Qa8+ Qf8
>>>>0:04	3/7	4.00	355447		36...Rxf4 37.Rxf4 Bxf4 38.Bxf4
>>>>					c3 39.Qd1 Qb7 40.Qd8+ Kf7 41.f3
>>>>0:07	3/8	4.87	709846		36...Rxf4 37.Rxf4 Bxf4 38.Bxf4
>>>>					c3 39.Qa7 h5 40.Be5 Qg6 41.Qb8+
>>>>					Kh7 42.Qxb3 hxg4 43.Qxc3 gxh3 44.Kxh3
>>>>					Qh5+ 45.Kg2
>>>>0:32	3/8	4.76	2874367		36...Qb7 37.Bb2 h5 38.Ne3 Bxf4
>>>>					39.Rxf4 Rxf4 40.gxf4 Qe4 41.Bxg7
>>>>					Qxf4+ 42.Kg1
>>>>0:54	3/8	4.71	4928413		36...Bxf4 37.Bxf4 Re6 38.Ne5 Qd5
>>>>					39.Kg2 Rb6 40.Qb2
>>>>1:41	4/9	5.06	9349513		36...Bxf4 37.Bxf4 Re6 38.Ne5 Qd5
>>>>					39.Kg2 Re7 40.Qc1 Rc7 41.Qb2
>>>>
>>>>ouch.... I don't feel so bad now when I hang a pawn.... ;-)
>>>>
>>>>jm
>>>
>>>14.4 million positions and a search depth of 4 ply?  What am I missing?
>>
>>a lot of extension and a different definition.
>>
>>I believe that the real depth is 9
>>
>>The meaning of 4 is probably brute force depth
>>with no null move pruning and no other pruning.
>>
>>The meaning of 9 is probably the real depth when chessmaster used only the null
>>move algorithm to prune.
>>
>>The fact that usually in endgame I see x/x+1 numbers and not x/x+5
>>supports my opinion because I see no reason to prune less in the endgame
>>(The opposite-endgame are the best candidate for more pruning rules
>>unless you talk about null move pruning)
>>
>>Note that I did not write chessmaster so
>>I do not know if my guess is correct.
>>
>>Uri
>
>The first number IS the brute force depth. All possibilities of plies of that
>first number (in this case, 4) have been searched. The second number is the
>MINIMUM extension depth. This is why Chessmaster can report a Mate in 15 (29
>plies) at depth 2/5, as it has done in this position (in less than one second,
>no less ;-):
>
>[D]7k/2p3p1/4Q2p/p3n3/2pBP2P/2P3P1/1r2q3/5RK1 w
>
>Time	Depth	Score	Positions	Moves
>0:00	1/3	0.00	5111		1.Rf8+ Kh7 2.Qg8+ Kg6 3.Qe6+ Kh7
>0:00	1/4	0.00	23042		1.Rf8+ Kh7 2.Qg8+ Kg6 3.Qe6+ Kh7
>0:00	2/5	Mate15	57975		1.Rf8+ Kh7 2.Qg8+ Kg6 3.Rf6+ Kxf6
>					4.Qf8+ Ke6 5.Qe8+ Kd6 6.Bxe5+ Kc5
>					7.Bd4+ Kd6 8.Qd8+ Ke6 9.Qd5+ Ke7
>					10.Bc5+ Ke8 11.Qe6+ Kd8 12.Be7+
>					Ke8 13.Bf6+ Kf8 14.Qe7+ Kg8 15.Qxg7#
>0:01	2/6	Mate15	106803		1.Rf8+ Kh7 2.Qg8+ Kg6 3.Rf6+ Kxf6
>					4.Qf8+ Ke6 5.Qe8+ Kd6 6.Bxe5+ Kc5
>					7.Bd4+ Kd6 8.Qd8+ Ke6 9.Qd5+ Ke7
>					10.Bc5+ Ke8 11.Qe6+ Kd8 12.Be7+
>					Ke8 13.Bf6+ Kf8 14.Qe7+ Kg8 15.Qxg7#
>

Interesting. My program Gaviota finds Mate in 15, with the same sequence
of moves in 18 seconds on a PIV 1.4 Ghz. Also, at ply 6 and I am very happy with
that. The interesting part is that Gaviota requires ~2Mega positions
where CM requires only 100K. In this particular position CM's tree is
20-fold leaner! I will have to work hard on trimming the fat!


Signature[1]: 2f2af0dc
7k/2p3p1/4Q2p/p3n3/2pBP2P/2P3P1/1r2q3/5RK1 w - - 0 1
+-----------------+
| . . . . . . . k |
| . . x . . . x . |
| . . . . Q . . x |
| x . . . n . . . |
| . . x B o . . o |
| . . o . . . o . |
| . r . . q . . . |
| . . . . . R K . |
+-----------------+

legal moves available = 40
       276   1       0.0   -10.67  Qe6-g8   Kh8xg8   Rf1-f2   Qe2-e1
                                   Kg1-g2   Rb2xf2   Bd4xf2   Qe1xc3
       785   1       0.0    +2.10  Rf1-f8   Kh8-h7   Qe6-g8   Kh7-g6
                                   h4-h5    Qe2xh5   Qg8-e6   Kg6-h7
                                   Bd4xe5
       978   1:      0.0    +2.10  Rf1-f8   Kh8-h7   Qe6-g8   Kh7-g6
                                   h4-h5    Qe2xh5   Qg8-e6   Kg6-h7
                                   Bd4xe5
      1551   2       0.0    +2.10  Rf1-f8   Kh8-h7   Qe6-g8   Kh7-g6
                                   h4-h5    Qe2xh5   Qg8-e6   <EMPTY>
                                   <-transp
      2400   2:      0.0    +2.10  Rf1-f8   Kh8-h7   Qe6-g8   Kh7-g6
                                   h4-h5    Qe2xh5   Qg8-e6   <EMPTY>
                                   <-transp
     10970   3       0.1      :-(  Rf1-f8
     19223   3       0.2      :-(
     21978   3       0.2      :-(
     97988   3       0.8    +0.00  Rf1-f8   Kh8-h7   Qe6-g8   Kh7-g6
                                   Qg8-e6   Kg6-h7
     99431   3:      0.8    +0.00  Rf1-f8   Kh8-h7   Qe6-g8   Kh7-g6
                                   Qg8-e6   Kg6-h7
    281747   4       2.4    +0.00  Rf1-f8   Kh8-h7   Qe6-g8   Kh7-g6
                                   Qg8-e6   Kg6-h7
    287259   4:      2.4    +0.00  Rf1-f8   Kh8-h7   Qe6-g8   Kh7-g6
                                   Qg8-e6   Kg6-h7
    698465   5       5.8    +0.00  Rf1-f8   Kh8-h7   Qe6-g8   Kh7-g6
                                   Qg8-e6   Kg6-h7
    734253   5:      6.1    +0.00  Rf1-f8   Kh8-h7   Qe6-g8   Kh7-g6
                                   Qg8-e6   Kg6-h7
   1706066   6      14.0      :-)  Rf1-f8
   1710738   6      14.0      :-)  Rf1-f8
   1790314   6      14.7      :-)  Rf1-f8
   1846161   6      15.1      :-)  Rf1-f8
   2273113   6      18.2  +Mat_15  Rf1-f8   Kh8-h7   Qe6-g8   Kh7-g6
                                   Rf8-f6   Kg6xf6   Qg8-f8   Kf6-e6
                                   Qf8-e8   Ke6-d6   <-transp
   2301528   6:     18.4  +Mat_15  Rf1-f8   Kh8-h7   Qe6-g8   Kh7-g6
                                   Rf8-f6   Kg6xf6   Qg8-f8   Kf6-e6
                                   Qf8-e8   Ke6-d6   <-transp
   4080652   7      31.6  +Mat_15  Rf1-f8   Kh8-h7   Qe6-g8   Kh7-g6
                                   Rf8-f6   Kg6xf6   Qg8-f8   Kf6-e6
                                   Qf8-e8   Ke6-d6   Bd4xe5   Kd6-c5
                                   Be5-d4   Kc5-d6   Qe8-d8   Kd6-e6
                                   Qd8-d5   Ke6-e7   Bd4-c5   Ke7-e8
                                   Qd5-e6   Ke8-d8   Bc5-e7   Kd8-e8
                                   Be7-d6   Ke8-d8   Qe6-e7   Kd8-c8
                                   Qe7xc7
   4185919   7:     32.4  +Mat_15  Rf1-f8   Kh8-h7   Qe6-g8   Kh7-g6
                                   Rf8-f6   Kg6xf6   Qg8-f8   Kf6-e6
                                   Qf8-e8   Ke6-d6   Bd4xe5   Kd6-c5
                                   Be5-d4   Kc5-d6   Qe8-d8   Kd6-e6
                                   Qd8-d5   Ke6-e7   Bd4-c5   Ke7-e8
                                   Qd5-e6   Ke8-d8   Bc5-e7   Kd8-e8
                                   Be7-d6   Ke8-d8   Qe6-e7   Kd8-c8
                                   Qe7xc7
Regards,
Miguel


>jm



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