## Friday, March 03, 2006

### Composition generator "Grigoriev"

I tested my empyrical formula's in a lot of situations with the Nalimov tablebases.
They didn't let me down.
Let me show you a random situation with two blocked pawns on the same file.

diagram 1

Where would you put the white king if you had the choice?
First you have to draw the draw zone.

diagram 2

The basic measure is the distance between the black king and the white pawn = 4 moves
The draw zone is based on the fact that the white king conquers the key square when the black king snacks the white pawn.

Center of the draw zone = c4 = key square black pawn
Diameter of the draw zone = 4 + 1 = 5 moves (white can afford to lose one tempo)

Then you draw the win zone.

diagram 3

Center of the win zone is the black pawn.
Diameter win zone = 4 moves.

Where you don't win or draw, you lose.

diagram 4

Red = loss zone
Then you have to find out where one king shoulders the other away when they walk on their ideal paths to their respective targets.

diagram 5

Yellow = interference zone
When the kings collide the impeded king loses a tempo.
If the white king hinders the black king, the win zone increases by one move.
When the black king hinders the white king, the loss zone increases by one move.

diagram 6.

The only thing you have to do now is to drop your white king on an interesting place and you have 3 brand new Grigoriev-like studies.
With hardly any calculation!
One solution guaranteed!
White to move.

This is of course a relative simple situation since the pawns are sitting ducks.
At the moment I'm trying to do the same with one or more ranks between the pawns.
I don't understand all aspects yet, but I allready found a few interesting things.
Heck, at this pace I'll never reach Lucena's position!
Btw, I ordered Secrets of rook endings from John Nunn.

1. Seriously, you should try to get a book published on pawn endings for beginners. You could review basics (key squares etc), and work up to this system you have worked up.

At the very least, it would be great if you combined all this stuff into a manuscript for we patzers to print out and study.

The most frustrating parts of the Tasc Chess Tutor for me were the king versus pawn endings. The explanations for certain moves were not helpful, and I just ended up memorizing some of the more difficult problems.

2. Tempo,
If i'm not mistaken White king on g4 with White to play is a straight win for white. Black to play a straight win for black coz white cannot defend pawn nor can prevent the black king to queen his pawn. White cannot reach the opposition field in time although he has four moves.

3. Montse, yes that is true.
g4 is at the edge of the green win zone. All other moves than 1. Kf5 don't win (=draw or lose)

4. How do you easily determine the interference pattern? I can easily check some king positions, by calculating it and see what the relative positions of the kings are? Is there a way to show them all at once.Would be nice!!