Free game analysis engine

I'm looking for a free engine that I can use to analyse my games. Which would you recommend?

Originally posted by moteutsch
I'm looking for a free engine that I can use to analyse my games. Which would you recommend?

Fruit 2.3.1. Very strong, allegedly stronger than Fritz although I cannot test that since Fritz doesn't run on Macs. I would think Fruit would do very well.

This data is old and does not reflect the latest versions. It also includes only engine testing done on my computers. I set the average rating at 2200, as most of the engines are quite a bit higher than that.

1 Rybka v1.0 Beta.w32 : 2473 76 73 122 86.5 % 2150 15.6 %
2 Hiarcs 9 : 2470 39 39 257 67.5 % 2343 23.7 %
3 Hiarcs8 Bareev : 2469 96 92 45 74.4 % 2283 28.9 %
4 Fritz 7 : 2465 52 51 163 69.9 % 2318 18.4 %
5 Fruit 2.1 : 2433 63 62 82 57.9 % 2378 32.9 %
6 Fritz 8 : 2430 50 50 158 61.7 % 2347 19.6 %
7 Fruit_21 : 2428 72 69 122 83.2 % 2150 15.6 %
8 Spike10a : 2406 56 55 126 61.9 % 2322 20.6 %
9 List 512 : 2381 37 36 310 68.1 % 2250 20.6 %
10 Glaurung : 2381 62 60 132 77.7 % 2165 18.9 %
11 Ruffian 1.0.1 : 2377 31 31 371 65.2 % 2268 27.0 %
12 SlowWV2 : 2373 58 57 138 68.5 % 2238 13.8 %
13 Spike 0.9 : 2369 38 38 253 62.1 % 2283 25.3 %
14 Naum 1.7 : 2364 72 70 95 74.2 % 2180 17.9 %
15 Aristarch 4.50 : 2362 37 36 265 61.5 % 2281 27.2 %

The two versions of Fruit listed are the same version, but run in separate environments--Arena and Fritz interfaces.

Originally posted by Wulebgr
This data is old and does not reflect the latest versions. It also includes only engine testing done on my computers. I set the average rating at 2200, as most of the engines are quite a bit higher than that.

1 Rybka v1.0 Beta.w32 : 2473 76 73 122 86.5 % 2150 15.6 %
2 Hiarcs 9 : 2470 39 39 257 67.5 % ...[text shortened]... ruit listed are the same version, but run in separate environments--Arena and Fritz interfaces.

I wonder why the Fritz interface would weaken an engine? Or is it the other way about?

Originally posted by Kepler
I wonder why the Fritz interface would weaken an engine? Or is it the other way about?

Different competition. The difference in rating is slight enough (5 Elo) that "weaken" is a stretch for the number of games played. Also I run some thematics with my engines, and test different books. Conditions are always equal for all the engines in the event, but some conditions might favor certain engines.

I'd say engines 1-4 are dead even, and 5-7 are too. Fruit is 5 and 7.

Fritz 7 running 35 points above Fritz 8 is the biggest surprise, it seems to me. Spike 1.0 is clearly stronger than Spike 0.9.

http://www.fruitchess.com/

Fruit 2.2 and 2.3 are now free to download, they used to be commercial. It is probably the best free engine you can get. It works under Arena, and also the Shredder GUI, I recently bought Deep Shredder 11 and Fruit works great under that interface.

Originally posted by IndianaSwift
http://www.fruitchess.com/

Fruit 2.2 and 2.3 are now free to download, they used to be commercial. It is probably the best free engine you can get. It works under Arena, and also the Shredder GUI, I recently bought Deep Shredder 11 and Fruit works great under that interface.

Got 2.3. Running a gauntlet against ten engines. Lost to Fritz 9, drew Anaconda 2, beat three others--all with White.

check out gambitfruit and toga (both fruit derivative freeware engines, both very strong),
and rybka 1.0 (free version of the current top commercial engine)

Fritz 11

I also like Fruit 2.3.1. It can handle either endgame tablebases or endgame bitbases, which can be helpful in analyzing endgames. (I prefer tablebase files. Bitbases will throw away unnecessary material, which can be confusing at times.)

Toga is a little stronger than Fruit, but there are too many versions of Toga and hard to keep them straight. Most of them use bitbase files, but I don't remember any of them using tablebases. (I could be wrong about this.)

Although Rybka 1.0 is very strong, I wouldn't recommend it for analysis. It doesn't have multi-PV capability, and it's buggy in the endgame.

Link for Fruit 2.3.1:
http://www.superchessengine.com/fruit.htm

Originally posted by Mad Rook
Toga is a little stronger than Fruit,

I don't think so.

Fruit 2.3 - Toga II 0.93 [B96]
Fruit Loops (1.7), 18.07.2008
[0.00;–0.53]
Intel(R) Pentium(R) 4 CPU 3.40GHz 3401 MHzW=12.8 ply; 543kN/s; 5,307 TBAs; Informant.ctgB=10.5 ply; 827kN/s; Informant.ctg 1.e4 B/0 0 c5 B/0 0 2.Nf3 B/0 0 d6 B/0 0 3.d4 B/0 0 cxd4 B/0 0 4.Nxd4 B/0 0 Nf6 B/0 0 5.Nc3 B/0 0 a6 B/0 0 6.Be3 B/0 0 Ng4 B/0 0 7.Bc1 B/0 0 Nf6 B/0 0 8.Bg5 B/0 0 e6 B/0 0 9.f4 B/0 0 Nbd7 B/0 0 10.Qf3 B/0 0 Qc7 B/0 0 11.0–0–0 B/0 0 b5 B/0 0 12.Bd3 B/0 0 Bb7 B/0 0 13.Rhe1 B/0 0 Be7 B/0 0 14.Qg3 0.00/11 10 b4 -0.53/11 9 15.Nb1 0.06/12 7 h6 (Qb6) -0.55/11 9 16.Bh4 -0.03/12 5 Nc5 (0–0) -1.26/11 8 17.e5 (Bxf6) -0.71/12 10 17...Nh5 -1.38/11 9 18.Qg4 -1.12/12 8 Nxf4 -1.32/11 9 19.Qxf4 -1.12/12 10 dxe5 (g5) -1.54/11 7 20.Nxe6 (Rxe5) -0.89/12 7 20...Nxe6 -1.43/10 4 21.Qf2 -0.80/13 9 Bg5+ (Bxh4) -1.36/11 34 22.Bxg5 -0.65/13 8 hxg5 -1.36/12 6 23.Bf5 (Qg3) -0.55/13 9 23...Rxh2 (Rc8) -1.44/11 7 24.Bxe6 -0.81/12 4 fxe6 -1.24/11 3 25.Rf1 -0.91/13 4 Rh8 -1.17/11 4 26.Qg3 (Nd2) -0.83/13 9 26...Be4 -1.23/10 8 27.c3 -1.01/13 7 Rc8 (Bf5) -1.13/10 8 28.Qxg5 -0.50/12 5 bxc3 (Rb8) -0.94/9 6 29.Nxc3 -0.69/11 6 Qa5 -0.67/9 3 30.Qd2 -0.13/12 5 Qa4 -0.69/9 3 31.Rfe1 -0.16/13 6 Rh4 (Bf5) -0.48/10 4 32.Rxe4 (g3) -0.52/13 3 32...Rxe4 -0.75/12 3 33.Kb1 -0.17/15 6 Qc6 -0.61/12 4 34.Nxe4 -0.29/15 6 Qxe4+ -0.62/12 2 35.Ka1 -0.47/15 4 Qd4 (Qd5) -0.62/12 3 36.Qe1 (Qe2) -0.47/14 5 36...Qf4 -0.78/11 2 37.g3 -0.34/14 3 Qf3 (Qg5) -0.74/11 2 38.Qd2 -0.37/12 4 Kf7 -0.61/10 6 39.Re1 -0.46/13 5 Qd5 -0.65/11 3 40.Rf1+ (Qe2) -0.56/13 2 40...Kg8 -0.76/12 2 41.Qf2 -0.66/15 4 Qb7 -0.78/12 3 42.Qe2 (Rd1) -0.45/14 7 42...e4 (Qb5) -0.72/12 3 43.Qh5 (Rd1) -0.04/15 3 43...Qc7 (e3) -0.55/11 4 44.a3 -0.28/15 2 Rf8 -0.34/12 3 45.Rh1 0.00/15 2 Qc4 -0.34/11 3 46.Qh7+ 0.00/16 3 Kf7 -0.14/4 0 47.Qh5+ (Rh4) 0.00/17 3 47...Ke7 -0.41/12 3 48.Qg5+ 0.00/17 3 Ke8 -0.28/12 3 49.Qg6+ (Qxg7) 0.00/16 3 49...Rf7 (Kd8) -0.34/12 1 50.Rh8+ (Re1) 0.00/13 2 50...Ke7 -0.70/9 0 51.Qg5+ 0.00/14 2 Kd6 -0.69/11 2 52.Qd8+ 0.00/14 2 Rd7 -0.62/11 4 53.Qf8+ (Qb8+) 0.00/14 2 53...Kd5 -0.62/11 2 54.Qf4 (Qe8) -0.29/12 2 54...Qe2 (Qd4) -0.69/9 5 55.Re8 (Qg5+) 0.00/12 2 55...Qd1+ (e3) -0.55/9 2 56.Ka2 0.00/13 0 Qc2 -0.51/10 3 57.Ka1 (Qg5+) 0.00/14 1 57...Qd3 (Qc4) -0.33/9 1 58.Rc8 (Qg5+) 0.00/13 1 58...Qd1+ (Qd4) 0.00/10 2 59.Ka2 (Rc1) 0.34/14 2 59...Qd4 0.00/10 1 60.b4 0.34/14 2 e5 0.25/10 1 61.Qg5 (Qg4) 0.25/13 2 61...Qf2+ 0.00/9 1 62.Kb1 (Ka1) 0.21/13 1 62...Qf3 (Kd6) 0.09/9 3 63.Kb2 0.18/12 1 Ke6 (Kd6) 0.09/9 3 64.Qg6+ 0.26/11 1 Qf6 0.05/9 0 65.Rc6+ (Qxe4) 0.28/12 1 65...Rd6 0.00/10 1 66.Qg4+ 0.22/13 2 Ke7 0.00/10 1 67.Rc7+ 0.22/13 1 Kf8 0.00/10 1 68.Qxe4 0.25/13 1 Qf2+ 0.00/10 1 69.Kb3 (Kb1) 0.18/13 1 69...Qxg3+ 0.03/9 1 70.Rc3 0.18/13 1 Qg5 (Qg6) 0.03/9 1 71.a4 (Rc5) 0.29/9 2 71...Qe7 (Ke7) -0.43/8 1 72.Rc8+ 0.18/10 0 Kf7 -0.52/9 1 73.Qf5+ (Qf3+) 0.09/10 0 73...Qf6 0.00/10 0 74.Qh5+ 0.35/10 1 Ke6 (Qg6) 0.00/10 1 75.Re8+ (Qh3+) 0.42/9 0 75...Kd5 (Kd7) 0.00/10 1 76.Qe2 (Qh1+) 0.41/10 1 76...Kd4 0.35/8 1 77.Rc8 0.47/8 0 Qf7+ 0.25/8 1 78.Rc4+ 0.78/9 1 Kd5 0.00/9 0 79.Rc5+ 0.72/8 1 Kd4+ (Ke6) 0.00/9 1 80.Ka3 (Rc4+) 1.90/11 0 80...Qe6 1.61/8 2 81.Rc1 (Rc2) 1.58/10 1 81...Qh3+ 1.59/9 0 82.Kb2 1.91/11 1 e4 1.56/9 0 83.Rc4+ 1.93/10 1 Ke5 5.52/10 1 84.Qxe4+ 1.67/9 0 Kf6 1.69/4 0 85.Qf4+ 5.21/10 0 Ke7 5.52/10 0 86.Rc7+ 5.21/11 1 Rd7 5.56/10 0 87.Rc3 5.24/9 0 Qe6 5.69/10 0 88.Re3 5.24/8 1 Rd2+ (Rd6) 5.95/10 1 89.Kc3 5.50/7 1 Rd6 6.37/10 0 90.b5 (Rxe6+) 5.72/6 0 90...axb5 6.09/9 0 91.axb5 (Rxe6+) 5.40/1 1 91...Kd7 (g6) 6.68/9 1 92.Rxe6 5.32/1 0 Rxe6 (Kxe6) 7.14/10 0 93.Qd4+ #15/1 0 Rd6 (Kc7) 9.69/11 2 94.Qxg7+ (Qa7+) #14/11 0 94...Ke8 #13/1 0 95.Qa7 #13/1 0 Rf6 #12/1 0 96.b6 #12/1 0 Rc6+ #11/1 0 97.Kd4 #11/1 0 Rc1 #11/1 0 98.b7 #10/1 0 Rd1+ #10/1 0 99.Ke5 #9/1 0 Re1+ #9/1 0 100.Kf5 #8/1 0 Rf1+ #8/1 0 101.Kg6 #7/1 0 Rb1 #7/1 0 102.b8Q+ #6/1 0 Rxb8 #6/1 0 103.Kf6 #5/1 0 Rb6+ #4/1 0 104.Qxb6 #4/1 0 Kd7 #4/1 0 105.Qc5 #3/1 0 Kd8 #3/1 0 106.Ke6 #2/1 0 Ke8 #2/1 0 107.Qe7# #1/1 0 1–0

Toga II 0.93 - Fruit 2.3 [C96]
Fruit Loops (2.7), 18.07.2008
[0.17;0.00]
Intel(R) Pentium(R) 4 CPU 3.40GHz 3401 MHzW=13.3 ply; 612kN/s; Informant.ctgB=14.2 ply; 369kN/s; 11,950 TBAs; Informant.ctg 1.e4 B/0 0 e5 B/0 0 2.Nf3 B/0 0 Nc6 B/0 0 3.Bb5 B/0 0 a6 B/0 0 4.Ba4 B/0 0 Nf6 B/0 0 5.0–0 B/0 0 Be7 B/0 0 6.Re1 B/0 0 b5 B/0 0 7.Bb3 B/0 0 d6 B/0 0 8.c3 B/0 0 0–0 B/0 0 9.h3 B/0 0 Na5 B/0 0 10.Bc2 B/0 0 c5 B/0 0 11.d4 B/0 0 Nd7 B/0 0 12.Nbd2 B/0 0 exd4 B/0 0 13.cxd4 B/0 0 Nc6 B/0 0 14.d5 B/0 0 Nce5 B/0 0 15.a4 B/0 0 Bb7 0.00/14 11 16.Nxe5 0.17/12 6 Nxe5 -0.14/13 7 17.f4 B/0 0 Ng6 -0.13/13 7 18.Nf3 0.18/11 9 Re8 (Nh4) -0.15/13 10 19.Qd3 (Bd2) 0.16/10 13 19...Nh4 (Qc7) -0.10/12 8 20.Ng5 (axb5) 0.31/10 8 20...h6 (Bf6) -0.25/11 5 21.e5 0.05/10 7 g6 -0.30/12 8 22.Ne4 0.00/10 6 c4 0.08/11 7 23.Qd2 0.26/10 5 Nf5 (dxe5) 0.04/11 6 24.Rd1 (g4) 0.06/9 5 24...dxe5 -0.61/11 4 25.fxe5 0.07/10 5 Bh4 0.19/13 32 26.g4 0.24/10 8 Ng3 (Rxe5) 0.26/12 9 27.e6 (Nxg3) 0.42/9 7 27...Qb6+ (Nxe4) 0.26/10 3 28.Qe3 0.42/11 6 Qxe3+ 0.26/12 5 29.Bxe3 0.42/12 3 fxe6 0.21/13 4 30.Nxg3 0.52/12 5 Bxg3 0.24/13 5 31.Bxg6 0.38/12 6 exd5 0.32/14 5 32.Bxe8 0.17/12 5 Rxe8 0.40/13 2 33.Bxh6 (Bf2) 0.11/12 7 33...b4 0.05/12 3 34.Rd2 0.14/11 6 Kh7 -0.36/13 3 35.Rg2 (Bg5) -0.17/12 6 35...Be5 -0.62/13 3 36.Bg5 -0.25/12 5 Bc6 (d4) -0.52/13 3 37.Rc2 -0.39/12 5 Kg6 (c3) -0.78/13 6 38.h4 -0.61/11 3 Bd7 -0.54/13 6 39.Rg2 (Rd2) -0.95/11 3 39...Bd4+ -1.16/13 4 40.Kf1 -1.27/12 3 Re4 -1.24/14 4 41.Rd1 (Re1) -1.27/12 3 41...Bxg4 -1.23/14 2 42.Rxd4 -1.51/12 3 Rxd4 -1.23/15 3 43.Rd2 -1.51/13 3 Rxd2 -1.10/15 2 44.Bxd2 -1.54/15 1 a5 -1.25/17 3 45.Be3 -1.65/16 4 Kf5 (c3) -1.64/16 3 46.Ke1 (h5) -1.81/16 5 46...Ke4 -2.21/16 4 47.Bc5 (Bf2) -3.60/17 9 47...d4 -4.47/17 2 48.Kd2 -3.91/17 3 c3+ (Bd7) -14.80/16 2 49.bxc3 -5.40/17 2 bxc3+ -16.39/18 2 50.Kc2 -13.16/20 49 Kd5 (Bd7) -18.29/13 3 51.Bb6 (Bd6) -7.10/18 4 51...Kc4 -#22/15 5 52.Kc1 -14.25/20 24 d3 -23.56/17 1 0–1

Originally posted by Wulebgr
I don't think so.

Fruit 2.3 - Toga II 0.93 [B96]
Fruit Loops (1.7), 18.07.2008
[0.00;–0.53]
Intel(R) Pentium(R) 4 CPU 3.40GHz 3401 MHzW=12.8 ply; 543kN/s; 5,307 TBAs; Informant.ctgB=10.5 ply; 827kN/s; Informant.ctg 1.e4 B/0 0 c5 B/0 0 2.Nf3 B/0 0 d6 B/0 0 3.d4 B/0 0 cxd4 B/0 0 4.Nxd4 B/0 0 Nf6 B/0 0 5.Nc3 B/0 0 ...[text shortened]... 3 51.Bb6 (Bd6) -7.10/18 4 51...Kc4 -#22/15 5 52.Kc1 -14.25/20 24 d3 -23.56/17 1 0–1

Filtering the CCRL lists for free 32-bit single CPU engines,

http://computerchess.org.uk/ccrl/4040/cgi/compare_engines.cgi?class=Free+32-bit+single-CPU+engines&print=Rating+list&print=Results+table&print=LOS+table&table_size=12&cross_tables_for_best_versions_only=1

and

http://computerchess.org.uk/ccrl/404/cgi/compare_engines.cgi?class=Free+32-bit+single-CPU+engines&print=Rating+list&print=Results+table&print=LOS+table&table_size=12&cross_tables_for_best_versions_only=1

Originally posted by Mad Rook
I also like Fruit 2.3.1. It can handle either endgame tablebases or endgame bitbases, which can be helpful in analyzing endgames. (I prefer tablebase files. Bitbases will throw away unnecessary material, which can be confusing at times.)

Toga is a little stronger than Fruit, but there are too many versions of Toga and hard to keep them straight. Most of ...[text shortened]... 's buggy in the endgame.

Link for Fruit 2.3.1:
http://www.superchessengine.com/fruit.htm

How do you know all this if you are a patzer as your profile claims? Or you are a Professor of chess engines?

Originally posted by Jie
How do you know all this if you are a patzer as your profile claims? Or you are a Professor of chess engines?

What, patzers have to be ignorant too? 😵

Originally posted by Mad Rook
What, patzers have to be ignorant too? 😵

Patzers don't have to be ignorant. They can read chess books and chess magazines and not be patzers anymore. It is useless from a practical standpoint of knowing engine x is stronger than engine y if you cannot even improve your chess. Don't tell me you cannot teach an old dog new tricks 😀