I compared Rybka 2.2, Fritz 10 ,Chessmaster 9000 and it looks like Rybka is strong.(If anyone can tell me where I can download Rybka 3 it would be great)

Rybka's evaluation is light years ahead of any other engine.  It's been estimated Rybka 3's positional eval is on par with an IM.  When you combine that with an extremely efficient and powerful search you get an engine that is far superior to anything else that's available.  Only Naum 4 can come anywhere close....

I thought Fritz was the most powerful looks like I was mistaken. I'd like to play against Rybka then, just for the matter of interest to see how much it would beat me by; obviously I would get destroyed from the start.

I think Rybka3 is not available for free. Chessmaster (I have the 10 000 version) is not as strong as Rybka or Fritz, but it has lots of study materials.

There are plenty of free engines out there for download if you want to get creamed. I mean for us there is little noticeable difference between playing a chess engine rated 3200 and a chess engine rated 2900. Both are going to rip us apart. 

Rybka 3 costs to buy and I can personally vouch for it's strength.  I have tested it uncut against Shredder, Fritz and Chessmaster and it prevails more often than not and the rest are draws.  This is probably why it won the World Computer Chess Championship as well.

Chessmaster Grandmaster Edition is a far superior learning tool to Rybka though as it can play you in a realistic human simulation.  Rybka isn't really programmed to be like that so it basically plays close to it's full strength and then randomly hangs a piece if you reduce it's elo.

Rybka is stronger than the other programs because it's algorythm is better. The algorythm is the most important part of a Chess program's strength, far more so than the hardware it is running on.  If you played with a weak program on the most powerful computer in the world then I would crush you every time with Rybka on my laptop.  The algorythm is the part that determines which move it will make based on it's research into the position/lines etc.  It scores a particular move based on this and then plays the best score.  Rybka does this slightly more accurately than other programs despite not necesarily 'thinking' deeper.  Slight advantages make big differences when playing at this level of Chess though which is why it is so much stronger.

Sorry if that is a bit long-winded, hope it helps you understand.

I found this. http://chessok.com/?page_id=357

here are some fun games between fritz and a GM

shredder 10 is a killer of human player of chess................hi from italy

Shredder 10 is a killer of almost everything at Chess.

Using the best Null Move heuristics coupled with algorithm.

Null move is a forced supression of certain lines/moves that the engine will NOT look at, these freeing valuable spacetime for deeper looks at worthwhile variations.

I am only a 1500 rated player so I assume it would mean nothing to me if my program was the best or just better than myself in analysis. With that said, what is teh best program to have to help with anaylsis. I am looking for something that will not only tell me the right move to make, but more importantly why it is better. Especially in the middle game the computer analysis tells me my move is inaccurate and that another is better, but often times I don't see the logic.

I'd definately say that any of the top engines will pretty much tell you the 'best' move for you since if you were remotely as good as them then you'd be a super grandmaster.  The reason for it being a good move is not so simple for the computer to explain like a person might.  A computer will tell you that it's the best move because no matter what the opponent does your position will be superior after a few moves due to material advantage or serious positional gain etc.  It cannot necesarily explain it in a way that you will understand as it doesn't play chess in the same way as you.  Computers are generally speaking tactical number crunchers, people are positional, strategic masters. Some programs like Chessmaster can analyse your game and explain why a few moves might be better tactically but I find it pretty limited when it tries to find strategic answers to superior moves.

Nicely written.Very Knowledgeable

Chessmaster.

It is very good and the best for learning and it worthwhile even for people in the 2200 range to study with and use its analysis.  It has many levels that can accomodate absolute beginners up to strong club.  It is not free and has issues running with Windows XP.

It's tutorials alone make it worth its price.

I made some matches in between Rybka 2.2 and deep shredder 11 uci.Then also Rybka is dominating

I have Rybka 3.0, and it isn't free as some earlier people have said. But I think it is the 'strongest' based on how it does in international tournaments. Based on computer tournaments, its rating is 3100+, where as Shredder is in the 2950+ range (not that that's a joke to play against, or anything, but think of the difference between a 1800 and a 2000)

I have Shredder as well, and I've had matches against the two engines on my pc, with Rybka usually winning. I think with a better system and the 'Deep' versions of both engines, Rybka would easily win in the end, due to programming efficiencies.

After my fifth move the engine was 'thinking' around 10min and it still didn't move so i did it away.

That happened to me on the fifth move to. Accept I let it carry on, and it was thinking for like 20min then I stopped playing it.

For a visual representation of a computer's thinking patterns, check out Thinking Machine. It's nowhere near as strong as Rybka, but it's pretty and you get an aesthetic idea of how a computer forces its way down certain favourable lines:

http://turbulence.org/spotlight/thinking/chess.html