It looks like strelka may be just a little stronger than rybka beta 1.0. Rybka beta is 8 pnts better than fruit 05/11/03 according to ccrl blitz. In my blitz, strelka 2 is 32 points better. similarly, rybka beta 1.0 is about 40 points better than shredder 10 (ccrl) . in my list, strelka is about 85 pnts better than shredder.
So I am guessing strelka 2.0 is now the best free engine available. it is probably just a bug-reduced version of rybka beta 1.0, so if you already own a later rybka, it is probably not worth much to you..
Details below, and of course I await more tests from others to make firmer conclusions.
Level: Blitz 1/1
Hardware: Dual Intel(R) Core(TM)2 CPU T7400 @ 2.16GHz with 2,048 MB Memory
Operating system: Microsoft Windows XP Professional Service Pack 2 (Build 2600)
Noomen/chessbase opening test set.
Program Elo + - Games Score Av.Op. Draws
1 Rybkav2.3.2a.w32 : 2942 29 28 450 70.3 % 2792 29.1 %
2 Strelka_2_0 : 2867 35 35 250 54.4 % 2837 33.6 %
3 TogaIIv3.1.2SE_P4_SSE2 : 2855 33 33 300 52.3 % 2839 30.0 %
4 Bright-0.2c : 2840 38 38 250 53.6 % 2815 21.6 %
5 Fruit-051103 : 2835 27 27 450 54.6 % 2804 32.2 %
6 kinguci_sel21 : 2791 34 34 300 50.5 % 2788 26.3 %
7 EngineShredder10UCI : 2782 27 28 450 46.0 % 2810 27.1 %
8 Spike1.2 : 2771 29 29 400 44.9 % 2807 28.8 %
9 Naum : 2738 45 45 150 51.7 % 2726 34.0 %
10 KingUCI : 2723 33 33 300 40.8 % 2788 32.3 %
11 kinguci_single : 2665 34 34 300 33.0 % 2788 31.3 %
12 Ruffian_210 : 2662 43 44 200 37.0 % 2754 23.0 %
2 Strelka_2_0 : 2867 250 (+ 94,= 84,- 72), 54.4 %
Rybkav2.3.2a.w32 : 50 (+ 10,= 16,- 24), 36.0 %
Fruit-051103 : 50 (+ 18,= 21,- 11), 57.0 %
EngineShredder10UCI : 50 (+ 24,= 13,- 13), 61.0 %
Spike1.2 : 50 (+ 26,= 13,- 11), 65.0 %
TogaIIv3.1.2SE_P4_SSE2 : 50 (+ 16,= 21,- 13), 53.0 %
strelka 2.0 evaluation
Moderator: Ras