Top 10 Free Chess Engine Recommendations

Top 10 Free Chess Engine Recommendation as of 12/7/13

Stockfish DD:  http://stockfishchess.org/
Komodo 5:  http://komodochess.com/
Houdini 1.5a:  http://www.cruxis.com/chess/houdini.htm
Critter 1.6a:  http://www.vlasak.biz/critter/
Gull 2.3:  http://sourceforge.net/projects/gullchess/
Bouquet 1.8:  https://sites.google.com/site/chessbouquet/
Rybka 2.3.2a:  http://www.rybkachess.com/
Strelka 5.5:  http://en.wikipedia.org/wiki/Strelka_%28chess_engine%29
Protector 1.5:  http://sourceforge.net/projects/protector/
Crafty 23.8:  http://www.craftychess.com/

As far as the interface (GUI) is concerned, I'm currently enjoying and recommending Scid vs. PC:  http://scidvspc.sourceforge.net/

I downloaded Stockfish DD (64-bit) and set it to 8 processors after 1.e4,e5 2.f4,exf4 3.Nf3,d6! and it evaluates the position as -.25 = at 7500 Kn/s after about 20 minutes, which is a bit too optimistic (or anything under at least -1.00) for white. 

Well, despite being down a pawn, the evaluation SHOULD certainly be something less than 1.00, as White already has some compensation for the sacrificed material.

It's White's move, he already has one piece developed and is about to further overtake Black in devevelopment by developing another.  He's two moves away from castling and upon doing so will develop his KR by putting it on the half open f file.

Whether all of this compensation is worth a full pawn or not has been debated for more than two hundred years... that's the King's Gambit for you. 

Other engine evaluations for that same position, some of which you're not going to like, since some are even more optimistic:

Komodo 6:  23 [-0.03]  4.Bc4 Be7 5.O-O Nf6 6.Nc3 Nxe4 7.Nxe4 d5 8.Bxd5 Qxd5 9.d3 O-O 10.Bxf4 Bf5 11.Nc3 Qd8 12.Qe2 Nc6 13.Qf2 b6 14.Rae1 f6 15.Be3 Qd7 16.Qh4 Bg4 17.h3  (158.37)

Bouquet 1.8:  21 [-0.12]  4.Qe2 c5 5.d4 cxd4 6.Bxf4 Nc6 7.Nbd2 Nf6 8.Nb3 Be7 9.O-O-O O-O 10.Nbxd4 Nxd4 11.Rxd4 Qa5 12.Kb1 Be6 13.a3 Rac8 14.Qb5 Qxb5 15.Bxb5 a6 16.Be2  (176.91)

Critter 1.6a:  22 [-0.16]  4.Qe2 g5 5.Qb5+ Nc6 6.Qxg5 Qxg5 7.Nxg5 Bh6 8.h4 f6 9.Nf3 f5 10.Nc3 fxe4 11.Nxe4 Nge7 12.Nf6+ Kf7 13.Ne4 Re8 14.Kd1 Bf5 15.Neg5+ Bxg5 16.Bc4+ d5 17.Nxg5+ Kg7  (71.98)

Houdini 3:  22 [-0.26]  4.Qe2 g5 5.Qb5+ Nc6 6.Qxg5 Qxg5 7.Nxg5 Bh6 8.h4 f6 9.Nf3 f5 10.Nc3 fxe4 11.Nxe4 Nge7 12.c3 Bf5 13.d3 O-O-O 14.Be2 Nd5 15.Nfg5 Rhf8 16.O-O Rde8 17.Bh5 Re7 18.c4  (129.14)

Deep Rypka 4.1:  20 [-0.33]  4.Bc4 h6 5.h4 Nf6 6.Nc3 c6 7.d4 b5 8.Bd3 Nh5 9.Ne2 g5 10.d5 a6 11.hxg5 hxg5 12.a4 b4 13.Qd2 c5 14.c3 a5  (347.10)

Naum 4.2:  19 [-0.34]  4.Bc4 h6 5.Nc3 Nc6 6.h4 Nf6 7.d4 Nh5 8.Nd5 Be6 9.Nxf4 Bxc4 10.Nxh5 Qe7 11.Kf2 O-O-O 12.b3 Ba6 13.Re1  (139.79)

Komodo 5 does not seem to use multiple processors. Nonetheless, it is holding its own against Stockfish 4 at blitz.

Correct. 
(Komodo 6 is the first Komodo version to use multiple processors.)

Stockfish DD blows Fritz 12 out of the water I go well over 10,000 kN/s sometimes on 8 cores

my comment was premature. Komodo scored the first win. However, when I shut off my box, Komodo had one win, 7 draws, and 7 losses. Still okay, given the single processor limitation.

@Ed, thanks for the list. Although I don't think Crafty is among the top 10 free engines, I'm glad you included it. I've always had a soft spot in my head...um, I mean in my heart for Crafty. I can't tell you why, exactly.

A few comments about Crafty - The engine is now up to version 23.8. Your Craftychess link in return links to Peter Skinner's site, where you can get the ver 23.8 compiles.

If you want the Crafty Chess Interface, you can get it at its new web site http://nightmarechess.com/crafty/  The interface is version 8, and it uses the version 23.6 engine.

Getting back to Peter's 23.8 compiles, he includes an x64 sse4.2 compile, an x64 sse3 compile, and a 32-bit x86 compile. It took me a while to realize that the x64 sse4.2 compile does NOT have the skill switch activated, but the other two compiles DO have an active skill switch. It appears that Bob still hasn't solved the time control problem that occurs when the skill switch is active at very low elo levels; The weakie Crafty will use too much time early in the game and will have to make multiple moves per second in the last 10 or 15 moves to reach the time control. You'll be stressing out wondering if it's really going to make the time control, or whether it's going to flag. I guess that adds an extra level of adventure to the games.

Ah!  Thanks for the info about version 23.8.  I edited my original post.

Notice I didn't say the top 10 strongest engines.  Crafty should be a part of everyone's collection regardless of its strength.  I believe that none of the other engines would be as strong as they are today if it weren't for Crafty.

Isn't Shredder 4 Classic free now? That's my favorite engine to play against, since you can easily set the ELO rating.

As far as I know, it's still a 30-day demo.

Please forgive a noob question, but do any of these have an advantage for a low rated amateur?

Hiya. You're an oldtimer here, I see.

There are two main reasons for using an engine; analyzing games, and using it as a playing partner.

You can use engines at the strong settings to help you identify the tactical parts of completed games. When going over games, you get more out of the study if you try to analyze the game yourself first (without the engine), then only later use the engine to spot the tactics.

Some engines can be set to play at a weak levels. You can play against these engines if there's some reason why you don't want to play against real people.

Thank you for that...I'll probably just stick to my old copy of Chessmaster11 and my RadioShack portable chess computer for now then...at least until I put in some more playing time...

I can almost match you - I have Chessmaster 9000 and 10th, and in some box somewhere, a RadioShack 1650 Fast Response (some RS marketing guy had a sense of humor) tabletop unit. I can still hear the ...beep!

( EscherehcsE wrote:

TheJelloman wrote:

Thank you for that...I'll probably just stick to my old copy of Chessmaster11 and my RadioShack portable chess computer for now then...at least until I put in some more playing time...

I can almost match you - I have Chessmaster 9000 and 10th, and in some box somewhere, a RadioShack 1650 Fast Response (some RS marketing guy had a sense of humor) tabletop unit. I can still hear the ...beep!)

2 1650s AND a SciSys Exploerer

King Arthur

Mephisto advanced travel

a couple hand helds

Chessmaster 7000,X, and XI

...and a shelf full of books I need to read...

That's pretty embarrasing...

How about Fruit??

ˁ˚ᴥ˚ˀ

Fruit's a good choice too.  I guess Fruit would probably fall in at # 11.

I tried to download SCID, but Norton anti-virus freaked out.

Great list.  

I, too, appreciate Crafty but Fruit is stronger, IMO.