Database basics - part 4

DATABASE BASICS -- PART 4

by Steve Lopez

Over the last couple of weeks in ChessBase Workshop we've been examining different dialogues in the database Search mask. We've seen a basic description of the "Game data" and "Annotations" dialogues; this week we're going to start an examination of the "Position" tab. This is arguably the most complex of the search tabs; consequently we're going to spend some time with it over two or three weeks. Although it's a bit more involved than the other search dialogues it's also pretty simple to use once you get the hang of it. Instead of providing a complete rundown of all features of this dialogue (as we've done with the previous two search tabs), we're going to start with some simple examples just so you can get the hang of how it works. We'll save the list of this dialogue's features for later.

Fire up Fritz8 (or one of its sister playing programs), open a database and bring up the Search mask (as described earlier in this series of articles). Click the "Position" tab at the top of the Search mask and you'll see the following dialogue:

This dialogue lets you search for board positions that occur within games in the database. As with other search tabs you'll use this dialogue to tell the program what to look for, click "OK", and the program will provide a list of games that qualify.

In using this dialogue, think of the double row of piece buttons to the right of the chessboard as your "box" of chessmen. Click on a button for the piece you want (such as a White King) and then click on the chessboard square upon which you want to place the piece. Let's look at a simple example. Click the "White King" button and place the King on g1. Then click the Black King button and place the piece on c8. [1] Make sure you've selected the radio button to the left of "'Look for' board" (we'll explain all of these radio buttons later):

[1] A shortcut for switching colors while placing the same type of piece is to right-click with the mouse. For example, if you've selected and placed the White King as in the above example and you now want to place a Black King, just right-click on c8 (instead of going back to the piece buttons and clicking on the Black King button). This also works in reverse: if you place, say, a Black Queen first (after clicking on the Black Queen button), you can place a White Queen by right-clicking on a square. This shortcut can save you a world of time when setting up board positions.

If you've followed the directions properly, your dialogue should look like the above illustration. Now just click the "OK" button to get a list of all games containing a position in which a White King is on g1 while a Black King is on c8. Why did we choose these particular squares? It's likely that most of the games (though not necessarily all of them) will involve the players castling on opposite sides of the board.

That's pretty simple. Let's try something a little more involved. Let's say that we want to find all games in which White has fianchettoed a Bishop to g2. This time we'll place a White Bishop on g2 and White pawns on f2, g3, and h2; this will give us the classic Kingside Bishop fianchetto formation:

Clicking "OK" here will bring up a list of all games in the database in which White has a Bishop and pawns on the squares indicated in the illustration.

Note that you do not need to set up a complete legal position in this dialogue (as you must with the "Position setup" dialogue, which we examined several weeks ago in ChessBase Workshop); the Position portion of the Search mask allows you to set up position fragments -- that is, partial positions. In the example above, it doesn't matter what other pieces are on what other squares; the program will always bring up games in which the Bishop and pawns are on the indicated squares.

This is exactly what the "'Look for' position" radio button does. By clicking it, you're telling the program, "I want to see a list of games in which these pieces are on these squares."

The "'Exclude' board" radio button does just the opposite: if you were to click that radio button and set up the same Bishop fianchetto position on the board, you'd get a (very long) list of all games in which White never fianchettoed his Kingside Bishop while pawns were simultaneously on f2, g3, and h2.

While you may sometimes find the "'Exclude' board" button useful on its own, it's usually going to be used in conjunction with a "'Look for' board" search. Here again an example will prove useful. Our previous search showed all games in which White fianchettoed his Kingside Bishop. But what if we want games in which the Bishop controls (at least most of) the long diagonal without being blocked by its own pawns? This is where the "'Exclude' board" feature becomes super-useful. Click the "'Look for' board" radio button and set up the Bishop and pawns as in our previous example. When you're done, click the "'Exclude' board" radio button and you'll see the chessboard go blank. Don't worry -- your fianchetto position is still there (just click the "'Look for' board" radio button to double-check this if you like). You've just reset the board to tell the program what the position can't contain.

Click the "'Exclude' board" button to get a blank board. Then click the White pawn button and place White pawns on f3, e4, and d5. What you've now "told" the program is that you want all positions in which White has fianchettoed his Kingside Bishop with pawns on f2, g3, and h2, but in which White does not have pawns on f3, e4, and d5:

Click "OK" and you'll get games in which those conditions apply: the Bishop has fianchettoed and isn't blocked by its own pawns (at least not up to d5 -- the square c6 might be another story).

When you look at the two rows of pieces to the right of the chessboard, you might be wondering what the two "circle" buttons are used for. These are "wild cards"; these circles represent any chess piece or pawn of that color. Let's go back to our White Bishop fianchetto example to see how we can use these wildcards. Our last search turned up games in which the Bishop wasn't blocked by White pawns on f3, e4, and d5. But let's say that we want to see games in which no piece or pawn of White's is blocking the Bishop's control of the diagonal. Instead of placing pawns on those three squares on the "Exclude" board, we'll place a white circle on these three squares instead:

Of course, we still have the Bishop fianchetto fragment set up on the "'Look for' board". Clicking "OK" will provide us with all games containing positions in which White has fianchettoed the Kingside Bishop but in which no White piece or pawn is sitting on f3, e4, or d5 to block the Bishop's path.

Now let's look for an ultra-powerful Bishop mastering the long diagonal with no pieces or pawns of either color on any square between f3 and b7. Leaving the fianchetto position on the "'Look for' board", set up the "Exclude" board to look like this:

Yes, Virginia, you can put more than one piece or wildcard on the same square! Click "OK" and get a list of all games in which a White g2-Bishop dominates the long diagonal with nothing on the squares b7, c6, d5, e4, and f3.

Please note that the side to move in a position doesn't matter in this dialogue. The Search mask is looking for positions without regard to which side is to move next.

You've doubtless noted that we haven't discussed the third radio button in the upper right of this dialogue: the "'Or' board". We'll remedy this omission now. The "'Or' board" is used when a particular piece or pieces can be on any square in a set of selected squares. Here's an easy example. Click the "Reset" button to get rid of our previous example. Now click the "'Or' board" button and place Black Kings on squares a8, b8, and c8 as shown below:

Clicking "OK" here will bring up all games in which the Black King is on a8 or b8 or c8 (this is why it's called the "Or" board). Why this particular search? All games in which Black castled Queenside will be part of the list, as well as games in which the King ran toward the a8 corner (even if Queenside castling wasn't part of the deal).

The "Or" board is a pretty handy tweak to know about when you want to find games with a common theme. For example, you could do an "Or" board search with White Kings placed on e4, e5, d4, and d5 to get games in which White centralized his King.

We'll look at one more part of this dialogue before class is dismissed for another week. Normally the Search mask only looks for positions within the main lines of games -- that is, the moves that were actually played. If you want the search to include positions from variations in any annotated games, click the "Include lines in search" box (located directly above the "OK" button) and the program will search for the position fragment in the replayable variations that might be included in the games in addition to finding qualifying positions in the main moves of the database's games.

We've started our investigation of the Position tab in the Search mask, but there's a lot more yet to come. We'll look at some more position searches in next week's ChessBase Workshop; until then, have fun!

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© 2004, Steven A. Lopez. All rights reserved.