“Creeping” chess analysis in Fritz/Rybka

In the previous blog post we examined a basic use for the “Infinite analysis” feature in the Fritz “family” of chess playing programs (Fritz, Rybka, Hiarcs, Shredder, and Junior). This time around we’re going to learn another way to use this feature, a method which is a bit more time-intensive but which yields interesting results.

In that last post we decided to examine the position which arises after the moves 1.e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Qe2 b5 7. Bb3 O-O 8. c3 d5 9. exd5 Bg4 10. dxc6 e4 11. d4 exf3 12. gxf3 Bh5 13. Bf4 Re8:

Fritz12 and Rybka4 chess playing computer software from USCFSales.com

…a variation I’d found in a book on chess openings, and which was evaluated by the author as giving Black some counterplay as compensation for the material. We used “Infinite analysis” mode to evaluate that final position (after 13…Re8) to a depth of 23 plies (half-moves).

Chessplaying computers, as fast as they are and as deeply as they look ahead, still suffer from the same essential problem from which humans suffer: they can only see so far ahead from a particular position. If you were playing the White pieces in a face-to-face chess tournament and had to analyze the position shown above, you would have a finite amount of time in which to select from several candidate moves. You would think about four or five moves, narrow the choices down to one or two, and then try to look as far ahead as you could to see what would happen.

Correspondence chess players, on the other hand, have an analytical advantage over face-to-face players, in that they can physically move pieces around to their heart’s content, write down moves and variations, and (after they’ve settled upon a particular move) create a huge tree of analysis showing the possible consequences of that move. Back when I was a correspondence chessplayer I used to record my moves and analysis using ChessBase as my “notebook”. After a particularly interesting game, my opponent asked if I would send him my analysis. I sent him a pack of over thirty printed pages of analysis for that one game.

That’s a fair bit removed from what an over-the-board player can accomplish analytically. And there are parallels between these processes and using “Infinite analysis” mode in Fritz, etc. In our previous post we demonstrated how to use a chessplaying engine to analyze from a given position, just the way an over-the-board chessplayer analyzes in a face-to-face game. But there’s nothing preventing you from using “Infinite analysis” mode to analyze a position in the same manner as a correspondence player would do.

We’ll start with the same steps to enter and save a position as we followed in the last blog post. Next we’ll click on the final position to highlight it, hit the “T” key (to take back the move), then make the same move again so that it appears as a variation line:

Fritz12 and Rybka4 chess playing computer software from USCFSales.com

Click on the picture for a larger view

Then we’ll click the “Infinite analysis” button:

Fritz12 and Rybka4 chess playing computer software from USCFSales.com

Click on the picture for a larger view

…to have the engine begin analyzing:

Fritz12 and Rybka4 chess playing computer software from USCFSales.com

Click on the picture for a larger view

How deep (in plies) you wish to have the engine analyze is, as we’ve seen, up to you; it depends in large measure on your hardware and how long you wish to spend on the task. For the purposes of this demonstration, I’m going to use Fritz12 and have the engine analyze to a depth of around 17 or 19 plies. When Fritz12 completes the seventeenth ply, I’ll hit the spacebar on my keyboard to have Fritz make the move on the chessboard, which also adds the move to the Notation pane:

Fritz12 and Rybka4 chess playing computer software from USCFSales.com

Click on the picture for a larger view

When you do this, you’ll notice that “Infinite analysis” doesn’t stop; however, it’s now analyzing the new board position (the one after 14.Bg3 in the example we’re using). After another seventeen ply search, I’ll hit the spacebar again to add another move to the variation:

Fritz12 and Rybka4 chess playing computer software from USCFSales.com

Click on the picture for a larger view

…and I’ll continue the process for as long as I wish, “creeping ahead” one move at a time and having Fritz analyze from each new position; that’s why I refer to this (in the title of this blog post) as “creeping” analysis:

Fritz12 and Rybka4 chess playing computer software from USCFSales.com

Click on the picture for a larger view

And because Fritz is analyzing from a series of successive positions (as would a correspondence player) rather than from a single starting position (as would an over-the-board player), the specific moves you’ll receive using each of the two methods will likely be quite different.

Of course, there is a way to have Fritz or another chess engine create this style of “creeping” analysis automatically without the user needing to hit the spacebar each move. We’ll learn about that the next time around. Until then…

Have fun! – Steve Lopez

Chessplayers who have purchased their ChessBase brand chess computer software from USCFSales can receive free technical support and advice on their purchases straight from me; just shoot me an e-mail (steve@uscfsales.com), but please remember to include the USCFSales order number from your ChessBase software purchase. – Steve

Copyright 2011, Steven A. Lopez. All rights reserved.

Advertisements

3 Comments

Filed under chess, Chess DVD, Chess playing software, Chess software, Chess Tiger, ChessBase, Fritz, Hiarcs, Junior, Rybka, Shredder

3 responses to ““Creeping” chess analysis in Fritz/Rybka

  1. Hi Steven,
    According to USCF CC (correspondence chess) rules use of chess playing programs is forbidden:

    “You cannot use a computer or computer program
    (chessplaying algorithms) to evaluate a game, but you
    may use computers for record keeping and databases.”

    And since you say to be in charge for
    USCFSales ChessBase technical support
    I wonder how then you encourage use of Fritz analysis/evaluation for CC.
    Can you explain please.

    BTW “ChessBase brand chess computer software” sounds too wordy,
    isn’t it just: ChessBase (chess) software?

    Regards
    iatelier

  2. “And since you say to be in charge for
    USCFSales ChessBase technical support
    I wonder how then you encourage use of Fritz analysis/evaluation for CC.
    Can you explain please.”

    Please provide a quote where I “encourage” the feature’s use for correspondence analysis.

    Oh, wait — you can’t. Because I didn’t.

  3. Pingback: “Deep position analysis” in the Fritz/Rybka chess playing program | USCFSales

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s