Endgame Studies & Training 2
At the end of this article I present 3 easy exercises, the solutions are shown in Part 3 in a few days.
The Rule of the Square is probably one of the first endgame lessons that are shown to beginners. It is a very easy method to see if a pawn can reach its promoting square or if the opponent's King can stop him.In the first diagram below it depends on whose turn it is. You have to imagine a diagonal from the pawn's square b4 to the 8th rank, so from b4 to f8, and this shall be the diagonal inside a square b4-b8-f8-f4.The rule says now if the opponent's King is inside this square or can enter it with his next move, the pawn can be stopped by the King! By saying "enter" it is enough to reach the border of the square. Right now, the black King is on g4 and outside of the square (b4-b8-f8-f4) but if it is Black to move he can simply reach the border of the square Kf4 or Kf5. Both of these moves guarantee to prevent the pawnfrom promoting. If it is White to move and the pawn advances to b5 --> the relevant squares gets smaller (b5-b8-e8-e5), and now the Black King is unable to reach it, so the pawn will be able to promote!
The second diagram shows a special situation. According to what I said before we would have a square a2-a8-g8-g2, and if it is Black to move he could enter the square resp. reach its border by Kg3 or Kg4.But we have to keep in mind that the pawn can advance two squares from the second rank to a4 in this case. Therefore, we need to treat the white pawn as if it was placed on a3!! For that reason the square goes a3-a8-f8-f3, and no matter whose turn it is, White cannot be stopped from promoting its pawn.
Finally, let us look at some other easy but educative examples we beginners should exercise a lot ;) It is White to move.
Exercise 2: It is obvious that White to move will win, but how should Black move to draw?
Exercise 3: Black to move and win!