ELECTRONIC T-NOTES


CHESSBASE USA'S WEEKLY ON-LINE NEWSLETTER


FOR THE WEEK OF JANUARY 10, 1999


16-BIT ENGINES IN FRITZ5.32

by Steve Lopez

At least twice a day I'm asked "How come Hiarcs6 and Junior4.6 don't work when I click on them in Fritz5.32?" The answer is very simple: because Hiarcs6 and Junior4.6 don't come with Fritz5.32 -- they need to be purchased separately.

What you're seeing in the engine list is the link file (or "thunking code" -- I think I'll stick with "link file") that allows the 16-bit Hiarcs6 and Junior4.6 .dll files to work as engines (.eng files) within the 32-bit Fritz5 interface. The link files are installed automatically; all that the owners of Hiarcs6 and Junior4.6 need do is copy the required .dll files into the Engines folder to make them work in Fritz.

If you don't own Hiarcs6 or Junior4.6 and have no plans of purchasing them, you can simply delete the Hiarcs6.eng and Junior46.eng files from your Engines folder and you'll no longer see them in your list of inactive engines.

MORE ON HASH TABLES

by Steve Lopez

I've heard from quite a few customers who claim that setting the hash tables in our various playing programs doesn't work. Actually, it does, but requires following a procedure that's not particularly obvious.

To properly set the hash tables for an engine, move all of your engines to the "Inactive engines" box. First set the hash table size, then move the engine to the "Active engines" box. If you try moving the engine first, followed by setting the hash size, it won't work.

Also, be careful not to overrun the total amount of available RAM for your hash tables when loading multiple engines (when using one engine as the tactical engine and another as the positional engine). For example, if you have 24 Mb RAM listed after "Free RAM" on the screen, don't try loading two engines with 16 Mb RAM each. You should instead select the "Adapt all hash tables" box before loading the first engine at 16 Mb RAM. Then load the second engine without making any further hash table adjustments. Each engine will now have access to the full 16 Mb RAM.

COMPARATIVE ENGINE ANALYSIS IN FRITZ5.32

by Steve Lopez

One of the interesting new features of Fritz5 is the ability to have more than one chess engine analyze a game. This is very easy to set up and use.

Load a game from a database. Click on the Levels menu, select Engine Research, and then Compare Analysis. You'll see this window appear:

Select which side you want the engines to analyze. Then you can use the "New" button to load an engine. You'll see a window like this:

You can select an engine from the list. Clicking on "Engine parameters" will let you set any configurable parameters for the engine you're selecting (note: not all engines have configurable parameters). You can also set the hash table size (for more on hash tables, please refer to the Electronic T-Notes issue for September 27th, 1998).

Here's a neat tweak for you to use: by clicking "Variation color" you can choose a color for the engine's variations to appear in the game score. This is very useful when you have multiple engines analyze a game, as it helps you differentiate between the analysis of the various engines when you replay the game later.

Once you've selected your engines, you can set the time or depth per move. Let's look at an example. Let's assume you've set the time for 180 (approximately 3 minutes a move) and loaded Fritz5.32, Crafty 16.2, and Comet A98 as your engines (in that order of selection). Fritz will analyze the game at about 3 minutes a move, writing its analysis into the game and coloring the analysis in the color you selected. When it's finished, Crafty will begin analyzing the game at about 3 minutes a move, etc. When it finished up, Comet will load and analyze the game.

Consequently, you don't want to go crazy when loading engines. If you load ten engines at five minutes a move to analyze a sixty-move game, you'd better be prepared to let your computer run for a few days.

Keep in mind, too, that the number of seconds per move is a guideline. The engines frequently take longer to analyze each move. This is because when their allotted time is "up", they will try to finish the ply they're working on before proceeding to the next move. If you set the time too high (depending on your processor speed), you'll find that a single engine might take a day or more to analyze a single game. As an example, I used to have Fritz3 analyze for five minutes a move on my old 386 machine; it would finish the analysis in a few hours overnight. I tried having it analyze at the same time limit on my Pentium and found that it was taking eighteen to twenty-four hours (or more!) to complete a game.

Why was this happening? Because the Pentium was faster, it was reaching a greater ply depth in the five allotted minutes. However, when the five minutes was up, Fritz was bent on completing its current ply search. Everytime you add a ply to a search depth, you're exponentially increasing the number of positions that a chess computer has to analyze to complete that ply. As it turns out, that last ply had more positions in it than all of the previous plies combined. This means that Fritz was searching, say, 12 plies deep in the first five minutes, but was taking an additional fifteen minutes to search that last (13th) ply, adding up to a twenty minute search total per move.

I find that on my Pentium, a two to three minute search is sufficient to get a good analysis without causing Fritz (or any other engine) to take an unacceptible amount of time to finish the game.

So keep in mind when setting the time or depth parameters (which are mutually exclusive, by the way) that you're going to have more than one engine analyze the game. If you select three engines, it's equivalent (timewise) to analyzing three games.

Selecting "Node count" means that the engines will display the number of positions they considered in analyzing each move. This is useful in comparing engines to see which is the fastest searcher. "Erase old annotations" does just what it says: replaces any previous annotations with those from the new session.

Comaparative analysis is a neat feature, especially useful for those of us blessed with multiple computers or owners of computers that see a lot of downtime. You can have more than one strong player give you its "opinion" of a game and you can also compare the "styles" of different engines.

Until next week, have fun!

You can e-mail me with your comments, suggestions, and analysis for Electronic T-Notes. If you love gambits, stop by the Chess Kamikaze Home Page and the Yahoo Chess Kamikazes Club.