BASE BASICS 4

SIMPLE MIDDLEGAME SEARCHES

by Steve Lopez

The most basic form of middlegame search is the position search. Fritz5 allows the user to perform some basic position searching, using either complete board positions or position fragments.

Correspondence chess players are especially fond of searching for a specific complete board position. There are two ways to conduct such a search and both are pretty easy to perform.

The first applies if you've created a tree for the database you're searching. A typical method for a correspondence player (one the opening of a game is defined) is to create a database of games that use the opening in question. For example, after 1.d4 Nf6 2.c4 e5 is played, you would do a search for all the Budapest Defense games in your collection and put them in a separate database. Then you'd create a tree for your new database.

Simply set up the board position in question (with the proper side to move), whack the [F11] key, and you'll have a list of all the replies from the games in the database, complete with statistical information. If you want to see specific games in which the position occurred, click (using the right mouse button, not the left) in the tree window. Click "search games" in the menu that appears and Fritz will display a list of the games. You can load and play through the games normally, just as you would from the database screen.

There's a second way to do a complete position search in Fritz5, one which doesn't rely on having a tree for the database. Set up the board position in question and click the "Database" icon. Click the "Search" button. This will call up the standard Search mask. Click the "Position" button. A new window will appear with the heading "Define position search".


This is the standard position search window. This is where you tell Fritz what to search for when you want to find specific positions in games from your database.

The next step is to click the "Copy board" button. This will copy the position you set up in the main Fritz screen to the board in the position search window. This tells Fritz that you want it to find only the games in which this specific board position appeared. Once you have the position on the board in the position search window, click the "OK" button. This will kick you back to the Search mask. Notice that the box next to the "Position" button now has an "x" in it. Click the "OK" button and Fritz will search the database for all games in which that position appeared in the main moves of the game (not variations). You can load the games normally right from the database screen.

One thing to be aware of: Fritz will automatically set the "First", "Last" and "Length" values to try to match the game the position came from (i.e. if you load a game, go to move 12, and use "Copy board", Fritz will set the values to 10, 1, and 12 respectively). Also be aware that there is a flaw in the window -- the words "Last" and "Length" are inadvertantly switched in some versions of Fritz5 (in my copy, Fritz sets the "Length" for 12, which obviously appears in error). The top box is "First", the middle box is for the "Length" value, and the lower box should be for the "Last" move. See the illustration on page 70 of the Fritz5 manual for the correct locations of the windows. When Fritz sets these values automatically, they will be correct; however, you may want to broaden the width of the search by a few moves (as explained in the next paragraph).

These values are important for speeding up Fritz's searches. If you're searching for a position that could only appear after 8 moves for each side, set the "First" value to 7 (you'd use 7 instead of 8 to give the program a bit of leeway). Likewise, you'd set the "Last" value to 10 or 11.

Why set these values at all? Because Fritz is searching through every gamne in the database. If you set the values to 7 and 11, Fritz will only examine the moves numbered 7 through 11 for each game, vastly speeding up its search (compared to, say, searching all moves bewteen 5 and 35). So double-check the way Fritz sets these values. You might want to expand the area of search by a move or two (to allow for transpositions).

Once you've loaded the position and set the values, you click "OK" to return to the Search mask. You can now combine the position search with other types of searches (for example, you could look for a specific board position from games in which White won between 1995 and 1997). This gives you a lot of flexibility and variety in the types of searches that you can perform.

The next time we explore some "Base Basics" we'll learn to search for position fragments. Until then, have fun!

Your questions, comments, and submissions are strongly encouraged.

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