Buy 3 chess training programs for the price of 2
Order any two training programs in our online chess shop and get a third training program absolutely free. If your order is more than $120 / €100 Euro, you will get additional present.
New CT-ART 5.0 combines three excellent courses guiding you from beginner to advanced level.
|ChessOK.com » Refuting Fischer|
Refuting Fischer 07 February 2008
For comparison, Fischer showed Olafsson the game Saidy – Fischer (USA ch. 1963), which he said was clearly used as a model when the Karpov – Kasparov endgame was created. This is the position after White’s twenty-third move:
All other values in this dialog box are set to their default settings. Since “Ignore colors” is selected the search will also find positions where Black has the knight and White has the bishop. The result is a list of all games where the material is equivalent to the positions shown above.
I started by limiting the search to positions where none of the pawns had crossed the midline by more than one square. If I didn’t find what I was looking for, I could always relax this requirement and search again; note that in the diagrams above none of the pawns have crossed the midline.
There are at least two different ways to search for such positions in Chess Assistant:
I preferred CQL for two reasons. First, because it is simply the most powerful search tool available, and second, because it allows me to store the searches (CQL queries) as text files. These are then easy to modify when you want to alter the search criteria. Note that you can also save other types of searches in Chess Assistant, but CQL queries are easier to manipulate once you master the basics.
The CQL query below is a modified version of the one I originally used. It consists of two main sections. In the first, we see a repeated use of the :piececount keyword. This is used to specify the number of different types of pieces on the board. The second section of the query describes the location of the pieces by using so-called piece designators.
The :piececount keyword is best understood by looking at a couple of examples.
This matches a position where there is exactly one (“1”) white bishop (“B”) on the board. Note that this doesn’t say anything about the number of other types of pieces. White pieces are specified using uppercase letters (P, N, B, R, Q, K) and the black ones using lowercase letters (p, n, b, r, q, k). You can also specify several different types of pieces by enclosing them in square brackets:
This matches a position where there are no rooks or queens on the board and also no white knight or black bishop. In other words, the only allowed pieces are pawns, white bishops and black knights.
The piece designators describe the position of the pieces. In the simplest case, when a piece must be on a specific square, we can write it like this:
This means that there must be a white pawn (“P”) on d4. If we want to search for a white pawn on a2, a3, a4 or a5, we can write it like this:
Note that you can put several piece designators on the same line in a CQL query as shown below. The most mysterious piece designator in the CQL query is the following:
This piece designator matches a position where there is a white bishop (B) on a dark square. The squares listed in the brackets are all the dark squares on the board.
Here is the whole query and, as you can see for yourself, it is mostly composed of :piececount keywords and piece designators. The comments (starting with a semicolon and reaching to the end of the line) show where each of the two main sections begin:
; The number of pieces
:piececount B 1
:piececount n 1
:piececount P 6
:piececount p 6
:piececount [NRQbrq] 0
; The location of the pieces
P[a2-5] P[b2-5] P[f2-5] P[g2-5] P[h2-5]
p[a4-7] p[b4-7] p[f4-7] p[g4-7] p[h4-7]
I described the basic structure of CQL queries in the December 2007 column, including the “match” and “position” keywords. The :flipcolor and :flipvertical keywords, which you can see near the end of the query, are very powerful. If you look at the four diagrams above, I would only find positions similar to the one on the top left without these keywords. The effect of :flipcolor is to transform the query so that it also finds the positions shown on the right hand side and :flipvertical allows me to find the types of positions shown at the bottom. So, with the help of these two keywords, a single CQL query allows me to find the four types of positions that are illustrated above.
Another interesting game was Fairhurst – Keres (Hastings 1955). Realizing that my task was complete, I called Olafsson and sent him all the games I had found. I wondered how Fischer would react when he saw the games. Yet I didn’t have to wait long. Olafsson called me after meeting with Fischer, who had recognized the Fairhurst – Keres game when he saw it. After going through the games Olafsson was pleasantly surprised by Fischer’s reaction: “Unbelievable! Wow, great research.” and then he laughed. He never mentioned this position again to Olafsson, clearly feeling that his theory about the game being prearranged had been refuted.
Study chess online on Chess King Learn! Time-proven training courses, thousands of examples and exercises.
Start playing right now in your web browser on Chess King Playing Zone! Teams, tournaments, training, analysis and much more!
7-man Lomonosov Tablebases provide deeper-than-ever insight into chess endgame.
Download weekly chess database updates (containing 2000+ games) with latest tournaments and games in PGN and Chess Assistant format.
|About - Contact Us|
|© 2008 — 2010 ChessOK.com|