Player repertoire opening books

In ChessBase Workshop we've recently discussed opening repertoires at considerable length; this discussion dovetails nicely with a related question which I'm often asked: "Can you create opening books based on a specific player rather than an opening?"

Theoretically, you can create an opening book based on literally any collection of games. For example, you might do a search for all games containing a selection of minor pieces (let's say two Bishops against two Knights) and then create an opening book based on that selection of games. You could then look at the numbers to see if any particular openings have a tendency to lead to that type of endgame (this thesis has been the subject of a few chess books over the years). You might then play games using that opening book to see how often you yourself wind up in such an endgame. I don't know how useful this is from a practical standpoint; it would seem to be more for curiosity value than anything else.

But a somewhat more interesting use for opening books might be to create different books based on the repertoires of specific players. Hmmmm...

I have an old computer baseball game which lets you create teams composed of great players of the past. The game is mostly statistically-based (allowing you to add players if you have access to their season or lifetime stats) but also adds an optional element in which you can control individual players as an action-based game; in other words, you can see what it might have been like to bat against Nolan Ryan by controlling the batter while Ryan's on the mound.

That's the kind of thing we're discussing when we look at creating opening books based on specific players. You can make a new book based on the games of a past or current player, load it into Fritz, etc. as the default opening book, start a new game, and presto -- you're playing against that player's opening knowledge. You're not really playing against that player any more than you're really batting against Nolan Ryan in his prime in the above example, but it's about as close as any of us are going to get.

Let's follow the steps. It's easier to do this in ChessBase than in Fritz, but we'll concentrate here on using the latter program (I'm sometimes accused of paying more attention to ChessBase users at the expense of those using Fritz, so let's try to rectify that imbalance here).

Your first step is to start a new game; we're doing this merely to clear any game currently in the Notation pane. Go to the File menu, select "New", and then either "Blitz game" or "Long game". It doesn't make a lick of difference which one you choose -- you're not really starting a game, just clearing the information of the last one.

Next you'll create the new opening book. Go to the File menu again and select "New" as before, but this time select "Openings book". You'll get a dialogue which allows you to select the folder into which the book will be stored, plus lets you name the book.

Let's take a little detour for a moment. When you create opening books based on a particular player's repertoire, you're really going to create two books: one for the player's games as White and one for his games as Black. Why? If you combine all of a player's games into a single book, you're never really going to know whose repertoire you're playing against: his or his opponents' -- they'll all be lumped together. That's why we're making two books for a particular player. When we want to play the White pieces ourselves, we'll load the book containing the player's Black repertoire. You get the idea.

That brings us back to naming our new book. When we give the book a name, what could be simpler than using the player's name followed by a "w" or "b" for the piece color? So let's say we're making a book based on Mikhail Botvinnik's games as White -- we'll name our book "Botvinnink_w" and click "Open" (which really ought to say "OK" instead to avoid confusion).

Now we'll create a database to hold the games we'll find in our game search. Go back to the File menu, select "New", and then "Database". Once again you'll get a dialogue which allows you to select the folder to contain the database and to give the database a name. Since we used a simple mnemonic for naming the opening book, we'll do the same thing for the game database: we'll name it "Botvinnik_w".

Next we'll search the master database for all of Mikhail Botvinnik's games as White. In the game list window, go back to your master database by selecting it from the pulldown menu near the upper righthand corner of the screen. Select "Filter games" from the Edit menu to call the Search mask. Fill it in as shown below:

You'll note several important items in this dialogue. Since we're looking for Mikhail Botvinnik's games as White, we make sure to put his name in the fields next to "White". We type the name in just like a telephone directory: last name first, first initial last -- and it's important to use that initial because there's more than one player named Botvinnik in the database. We're also sure to uncheck the "Ignore colors" toggle, otherwise we'll get his games playing both colors. One more important fact: in the last couple of decades there has been a second player named "Mikhail Botvinnik" on the tournament scene, so we have to be sure to fill in both "Year" boxes so that we exclude this newer player.

After filling in the Search mask, we click "OK" and let the software pull up all the games with Mikhail Botvinnik as White. After the search is completed we'll hit CTRL-A to highlight all of the games, go to the Edit menu, and select "Copy". Returning to the pulldown menu to the upper right of the game list, we'll select our "Botvinnik_w" database; after we've opened it, we'll go to the Edit menu and select "Paste". We'll see a box asking for confirmation that we want to copy the games; after confirming it, the games will be copied from one database to the other.

Go back to the main chessboard screen. In the Edit menu select "Openings book" and then "Import games". Use the resulting dialogue to select the "Botvinnik_w" database, and you'll see this dialogue appear:

The first part of this dialogue confirms the number of games to be imported (which should be the number of games in the database). "Length" refers to the number of "plies" (half-moves) which will be imported; if you want your opening book to be fifteen moves deep for each player, you'd put a value of "30" into this box.

There are a pair of mutually-exclusive settings which let you further refine the importation of games into the opening book. "Absolute length" means that every variation imported into the book will be the exact numeric length you set, regardless of whether the variation is a main line or side variation. "ECO-relative length" means that odd side variations will be shorter. Since we're creating a book based on a player's real-life repertoire, we'd select "Absolute length".

Last we'd uncheck "Include variations" since we don't want any annotator's later ideas included, just the moves that Botvinnik actually played.

After filling out this dialogue, click "OK" and let the software do its stuff. When the book is compiled, you'll see a dialogue telling you how many unique positions are contained in the new opening book:

Now you can set up a new game (setting time controls, etc.), flip the board around so that the Black pieces are at the bottom, hit the spacebar on your keyboard to make Fritz play White, and now you're playing against Botvinnik's White opening repertoire. If you have a good imagination, you might even be able to picture the former World Champion sitting across the board from you.

How will you know when you've left "book"? As soon as Fritz stops moving instantly after your moves, as soon as the program starts "thinking" about its moves, you'll know that you've left its opening book.

That's basically how you create an opening book based on a real-life player's repertoire. There are some neat twists and variations you can put on this. For example, you can limit your search to a certain span of years: you might do a search for the games of a former World Champion and limit the search to the years he reigned, so that you could play against his "Championship repertoire". Another idea might be to limit your search to a certain span of ECO codes so that you can practice against just a part of that player's opening repertoire. For example, Garry Kasparov is famous for playing the King's Indian Defense, so you might do a search for his games as Black playing ECO codes E60 through E99 and create a book from those games. If you play White with that book loaded, you'd be playing against Kasparov's KID repertoire.

I won't say the possibilities are "limitless" but they're certainly very broad and, in any event, playing with such an opening book gives you another fun way to practice against the Fritz "family" of playing programs.

Until next week, have fun!

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© 2007, Steven A. Lopez. All rights reserved.