Fritz Guide

Fritz has for many years been one of the most popular and strongest-playing commercial chess programs. Fritz users tend to be interested in squeezing every last bit of chess playing ability out of the software, which explains why my friends at ChessCentral have always noticed a pattern in the phone calls they’re receiving from such users: a lot of folks are asking, "How do I optimize Fritz for maximum playing strength?"

There’s no "twenty-five words or less" answer for that question. While Fritz12 does have a "one-click"  optimization option (in the Home menu, as a subfunction under the "Levels" button), it's still very useful for you to know how to configure Fritz manually. One of the key features of Fritz that sets it apart from many other chess programs is that it’s easily configured; Fritz allows you to reset a wide range of parameters to alter the way it plays. We can’t hope to examine every feature in-depth in just a single article (I’ve written scores of articles and an entire CD on the subject), but this article will serve as a basic guide or primer on how to use these parameters to get the best performance out of Fritz. This article is aimed at two types of users: those who are playing against Fritz themselves (using it as a trainer or sparring partner) and those who are using Fritz in computer vs. computer competitions on the Internet chess servers.

Chess Engines

The first hurdle we face is the terminology. What exactly is a chess "engine"? An engine is the guts (or, more accurately, the brain) of a chess program. It’s the part that actually plays chess, that evaluates positions and decides on a move.

Fritz comes with several engines. Of course, there’s Fritz itself as well as some previous versions of Fritz. There’s also a version of Crafty, and possibly some others (depending on the Fritz version and your operating system; Windows Vista won't recognize older 16-bit engines).

Why would you want more than one chess engine? There are several reasons. You could load different versions of Fritz, for example, and compare their analyses to see how the program has evolved over the years. You could have both Fritz and Crafty analyze your games; since they’re written by different programmers, each engine brings something a little different to the proverbial table, and you'll sometimes see them offering radically different alternative variations to what you actually played in your game. Some engines are weaker than others; when you use the Elo rating slider in the "Handicap and fun" or "Rated game" modes you’ll see a lower range of ratings than you see when you load Fritz. This can be a very helpful tool for beginning or low-intermediate level chess players.

Note that what you actually see on the screen doesn’t change when you load a new engine (other than the engine name in the Engine analysis pane, and the logo on the Clock pane if you have this option selected), so you won’t need to learn any new menu commands or procedures. The engines are modular, which means you can just "unplug" one engine and plug another one in without changing what you see on the screen and without having to exit Fritz and load an entirely separate chess program. We’ll examine the engine selection dialogue a bit later in this article.

Your Hardware

When trying to crank the most chess playing strength out of your computer, your first consideration is hardware. It was a truism in days past that computer hardware (processor speed and available RAM) was crucial in determining the strength of a chess program; the farther ahead a program could see, the better it tended to play just because it saw everything (or as close to "everything" as programming techniques would allow). This is somewhat less the case these days; programmers are building more positional chess knowledge into their engines, so the programs analyze more slowly than in days past but "understand" (in concrete, positional chess terms) more of what they evaluate. But hardware does still play a big role. In general, the faster your computer and the more RAM available (particularly at longer time controls; see below), the stronger your chess program will play. A long technical discussion and direct hardware comparisons are outside the scope of this article, though, so just keep that last sentence in mind as we move onward.

Another way to express the idea is this: the better your system resources, the stronger a chess program will play. Plunking down a big chunk of money to buy a faster system isn’t something everyone wants to do; besides, there are ways to optimize your present system for better chess play. The simplest thing is to not run any other programs that aren’t absolutely necessary while you’re playing Fritz. This will free up RAM and processor cycles for Fritz’s use.

So close any programs you might have running, even ones running "in the background" (don’t have Excel or Word running during a game). Don’t be surfing the Web while Fritz is playing a game online against another computer. And the best place to look for system-hogging culprits is in the "tray": that little box on the far right of your Windows Taskbar which contains your computer’s clock and (most likely) several other little icons.

Some of these icons are pretty benign for the purposes of this discussion; you’ll likely see one for your audio volume and your video display properties. You can leave those alone. But you’ll want to disable most of the others, which represent what are called TSRs – Terminate and Stay Resident programs. These are programs that are running in the background on your computer (and are taking system resources away from Fritz), programs such as anti-virus, disk "doctors", crash guards, "instant messengers", and a host of others. You can usually disable these by clicking (or right-clicking) on them and choosing an "exit" or "disable" option from a popup menu. You might need to consult these programs’ Help files or other documentation for further information on how to do this. (However, if you’re using a firewall program and are playing chess online, you’ll want to keep your firewall running for safety’s sake.)

Fritz Software

Now we come to the fun stuff: the Fritz software itself. There are numerous program elements that go into cranking every last bit of playing strength out of the engine; we’ll try to take each of them in turn, but they do overlap a bit in places and we’ll try to cover them as simply and painlessly as possible.

The first concern is the time control of the game itself. Generally speaking, the more time a program has available for evaluation, the stronger it will play. That’s just simple logic, right? But (and there is always a "but"), there is something of a law of diminishing returns at work here. Every time a ply (half-move) gets added to the depth of a program’s search, the number of positions which must be evaluated to complete that ply increases exponentially. Here’s a quick, easy example. Let’s consider a (hypothetical) chess position in which it’s White's turn to move. He has thirty possible candidate moves in that position, each of which must be evaluated. To make the math easier, let’s also assume that for each of White’s thirty candidates, Black has exactly thirty replies. And White will have exactly thirty replies to each of those Black replies, and so on. Here’s how the number of positions increases exponentially with each successive ply:

    *      White's first move: 30 positions
    *      Black's first move: 900 positions
    *      White's second move: 27,000 positions
    *      Black's second move: 810,000 positions
    *      White's third move: 24,300,000 positions

and so on. Now computers can do this evaluating pretty fast: even on an older Pentium III 800 MHz machine, Fritz completes a full eight ply search in about a second and a half. It can typically finish the eleventh ply after about 2.5 minutes. But getting to, say, a fifteen ply search requires more time than could reasonably be expected in a typical chess game (though the faster the hardware, the less time this takes – on a 2.0 GHz machine, Fritz hits a search depth in the teens almost instantaneously). This is what I meant by a law of diminishing returns: a computer can look three to five moves (six to ten plies) very quickly, but deeper searches take more time, with each successive ply requiring more and more evaluating and thus much more time.

On the other hand this explains two curious, but seemingly contradictory, phenomena. The first is that computer programs are extremely good at blitz games against human opposition; a program has already worked out the possibilities for the next four moves in the time it takes you to identify a single candidate move (never mind spotting a couple of your opponent’s possible replies). The other is that human players have better chances to beat a computer at longer time controls, because humans tend to concentrate on a few candidate moves and the variations that arise from them, while computers have to try to evaluate as many possibilities as they can (and this is where the "law of diminishing returns" factors in).

In a nutshell, the golden rule concerning time controls is this: assuming that other parameters (to be considered later in this article) are configured correctly, a computer will always play to the best of its ability within the constraints of the allotted time.

The Openings Book

What are some of these "other parameters" we've been mentioning? The first one we’ll consider is Fritz’s opening book. An opening book is simply a library of tried and true openings (tested over years or even centuries of human chess play) that a computer program draws from to play solid opening moves. Without access to an opening book, a chess program will tend to play the same predictable moves over and over – it’s essentially forced to "reinvent the wheel" with each new game.

Fritz comes with a customized opening book. It’s already been "tweaked" for maximizing the
program’s performance (primarily by a strong player editing the move selections provided in the opening book). All you have to do is load the opening book. Depending on what options you chose when you installed Fritz, the opening book is likely already on your hard drive. But if you click the "Openings book" tab (in the Notation pane) and see nothing but a button that says "Load book", you'll need to give Fritz access to it. Put the Fritz Program-CD in the CD drive, click that "Load book" button, go to the CD drive (using the dialogue that appears), and double-click on the file Fritz12.ctg; this will load the book. If you want to copy it to your hard drive, go to the "Openings book" section of the Analysis menu, and then select the command "Copy tree to hard disk".

There are a number of ways for you to manually tweak the book once it’s loaded; you can see this dialogue by hitting F4 on your keyboar

 

 

A full discussion of this dialogue alone would require an entire article, so we’re going to do some short-cutting here (though you can consult Fritz's Help file to see some more information about this dialogue's options). Notice the three buttons on the left-hand side of this dialogue. Click the "Optimize" button to automatically load the parameters that the programmers have selected to get the best play from Fritz and then click the "OK" button.

You may have noticed a pile of options in the when you click the "Openings book" button in the Analysis menu. These allow you to add the information from database games to your opening book, merge two separate opening books, etc. You might be tempted to fool around with these to make Fritz’s opening book "stronger". In a word: don’t. Fritz’s opening book is already optimized for best performance and, in 99 cases out of 100, mucking around with it will actually hurt the performance of the program, especially in online games against other computer opponents. (However, if you're primarily playing against the program yourself as a training tool and want to see a wider range of openings in your games against Fritz, I heartily recommend Fritz Powerbook , which is a massive opening book compiled from hundreds of thousands of master and grandmaster games without regard to the strengths and weaknesses of how a computer plays chess; in other words, it’s a tool for human players who want to practice and experience more varied openings by having their chess programs play them).

Hash Tables

The next dialogue we’ll consider is the Engine selection dialogue which, in addition to letting you pick an engine, also gives you tools to maximize the engine’s performance. Hit F3 on your keyboard or go to the Engine menu and select "Change main engine" to get to the following dialogue: