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Subject: Re: Activity in Rookending/Same with Amy

Author: Pete Galati

Date: 16:13:07 02/28/01

Go up one level in this thread


On February 28, 2001 at 17:14:27, Sune Larsson wrote:

>On February 28, 2001 at 16:31:40, Pete Galati wrote:
>
>>On February 28, 2001 at 14:33:56, Sune Larsson wrote:
>>
>>>
>>>  3r4/7p/Rp4k1/5p2/4p3/2P5/PP3P1P/5K2 b - - 0 1
>>>
>>>  This is Tarrasch-Rubinstein, San Sebastian 1911.
>>>  Black is a pawn down and the b6 pawn is under attack. Passive
>>>  defence with 1.-Rd6 or 1.-Rb8 is doomed to failure. Rubinstein
>>>  grasps his only chance: To mobilize his rook and king.
>>>  Activity is vital in rook endings.
>>>
>>>  1.-Rd2! 2.Rxb6+ Kg5 3.Ke1  [3.a4 f4 4.a5 f3! is more than welcome to black.]
>>>  3.-Rc2 4.Rb5 Kg4! 5.h3+ Kxh3 6.Rxf5 Rxb2 and black drew without effort.
>>>
>>>
>>>  Test: Big + for your program if it chooses 1.-Rd2! combined with
>>>        activating the king.
>>>
>>>        Thumbs down if it chooses passive defence with 1.-Rd6 or 1.-Rb8.
>>>
>>>  Sune
>>
>>Can't say I understand Rook endings, but I would have personally protected that
>>pawn.  On the other hand, I consider getting the Rook to it's 7th rank pretty
>>important.
>>
>>Comet being a somewhat defensive type program protected the pawn with Rb8, I
>>don't understand protecting it from there.  It looked at Rd6 for less than a
>>second.
>>
>>Missing virtual instinct that Comet never comcidered Rd2 in 63 minutes?
>>
>>Pete
>
> Hi Pete, I think this ending is difficult for most (all] programs, Deep
> Fritz/Shredder, Junior, Tiger included. If a program could play this
> ending like Rubinstein, I'm sure we would have seen the post here...
> These endgames are strange - afterwards it looks so easy...
>
> Sune

Amy had about the same reaction as Comet did, and worked on it longer too.

Pete

    Amy version Winboard Version 0.7, Copyright (C) 2000 Thorsten Greiner
[........]
GamePhase: Middlegame
It    Time   Score  principal Variation
 1     0.0     ---  1. .. f4
 1     0.0  -1.632  1. .. f4
 1     0.0     +++  1. .. Kf6
 1     0.0  -1.568  1. .. Kf6
 1     0.0     +++  1. .. Rd6
 1     0.0  -0.352  1. .. Rd6
 1     0.8  -0.352  1. .. Rd6
 2     0.8  -0.544  1. .. Rd6 2. Ke2
 2     0.8  -0.544  1. .. Rd6 2. Ke2
 3     0.8  -0.464  1. .. Rd6 2. Ke2 Kf6
 3     0.9  -0.464  1. .. Rd6 2. Ke2 Kf6
 4     0.9  -0.656  1. .. Rd6 2. Ke2 Kf6 3. Ke3
 4     1.0  -0.656  1. .. Rd6 2. Ke2 Kf6 3. Ke3
 5     1.0  -0.592  1. .. Rd6 2. Ke2 Kf6 3. Ra7 h5
 5     1.0  -0.592  1. .. Rd6 2. Ke2 Kf6 3. Ra7 h5
 6     1.1  -0.720  1. .. Rd6 2. Ke2 h5 3. Ra8 f4 4. Rg8+ Kf5
 6     1.2  -0.720  1. .. Rd6 2. Ke2 h5 3. Ra8 f4 4. Rg8+ Kf5
 7     1.4  -0.592  1. .. Rd6 2. Ke2 Kf6 3. Ra7 h6 4. Ke3 Ke5
 7     1.7  -0.592  1. .. Rd6 2. Ke2 Kf6 3. Ra7 h6 4. Ke3 Ke5
 8     3.0     ---  1. .. Rd6
 8     3.6  -0.976  1. .. Rd6 2. a4 Kg5 3. a5 Rd1+ 4. Ke2 Ra1 5. Ra7 Rxa5
 8     4.2  -0.976  1. .. Rd6 2. a4 Kg5 3. a5 Rd1+ 4. Ke2 Ra1 5. Ra7 Rxa5
 9     4.6     ---  1. .. Rd6
 9     4.8  -1.328  1. .. Rd6 2. a4 Kg5 3. a5 Rd1+ 4. Ke2 Ra1 5. Rxb6 Rxa5 6.
                    Rd6
 9     4.9     +++  1. .. Rd1+
 9     5.0  -1.248  1. .. Rd1+ 2. Ke2 Rd6 3. a4 Rf6 4. a5 bxa5 5. Rxa5 Rd6 6.
                    Ke3
 9     5.1     +++  1. .. Rb8
 9     5.4  -0.992  1. .. Rb8 2. Ke2 Kf6 3. a4 Kg5 4. Ke3 h5 5. f3 exf3 6.
                    Kxf3
 9     5.6  -0.992  1. .. Rb8 2. Ke2 Kf6 3. a4 Kg5 4. Ke3 h5 5. f3 exf3 6.
                    Kxf3
[snip]
18   59:41  -1.168  1. .. Rb8 2. f3 exf3 3. Kf2 Kg5 4. Kxf3 Rd8 5. Rxb6 Rd3+
                    6. Ke2 Rh3 7. a4 Rxh2+ 8. Kd3 Rh3+ 9. Kc4 Rh4+ 10. Kb3
                    Re4 11. Rb4
18   99:46  -1.168  1. .. Rb8 2. f3 exf3 3. Kf2 Kg5 4. Kxf3 Rd8 5. Rxb6 Rd3+
                    6. Ke2 Rh3 7. a4 Rxh2+ 8. Kd3 Rh3+ 9. Kc4 Rh4+ 10. Kb3
                    Re4 11. Rb4
Nodes = 1918522858, QPerc: 70 %, time = 8668.79 secs, 221.3 kN/s
Extensions: Check: 95157866  DblChk: 336574  DiscChk: 1059852  SingReply:
4434081
            Recapture: 5844859   Passed Pawn: 22774318   Zugzwang: 1800
Hashing: Trans: 41323067/569415316 = 0 %   Pawn: 737949315/743321551 = 1 %
         Eval: 604838439/1348159990 = 0 %
EGTB Hits/Probes = 16427/93671
Hashtable 1:  entries = 2097152, use = 2053920
Black(1):

I'll be back.



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