Why fiddling works

 The subtleties of an endgame position can be made visible with the aid of an endgame tablebase. I already experimented with this with my composition generator Gregoriev back in 2006.

Let me experiment with that again. I'm trying to draw the diagrams in SCID

White to move

[FEN "5k2/8/8/8/1P6/8/8/3K4 w - - 0 1"]


The = area is a result of the rule of the square. If the black king is in the = area, then the white pawn is out of reach. The rule of the square is meant to avoid calculation and to replace it by visualization. What I'm looking for is to show areas, so that calculating is no longer a necessity, because you can see it.

The next step is to show the key squares.

White to move

The key squares are the circles. When the white king is on the key squares, he can promote the pawn. No matter whether he has the opposition or not.

The reason for that, is that when the white king is on a key square, he has a reserve move. That reserve move is represented by the exclamation mark. The king can pass a move by moving the pawn.

I noticed that opposition and triangulation are just special cases of corresponding squares.

White to move

In order for black to prevent white from making progress, he must step on the squares with the equal numbers as white. He can't do that in time. The next problem is shouldering. If white takes the wrong route, black can shoulder him away.

White to move

White must take the grey route (wrong route in red).

I'm going to try whether it is possible to see the corresponding squares and the shouldering routes instead of calculating them.