Originally posted by Alcra
Thanks guys, I now know what it means, but haven;t the foggiest "what it means!"
Can someone talk to me like a little child and explain it 🙂
Any lessons gladly absorbed.
idea 3: related (conjugated) squares
Invalid FEN inserted - 8/k7/3p4/p2P1p2/P2P1P2/8/8/K7/ w
White would win if he could get the king to b5 or g5. To get him on g5 is a matter of gaining enough tempi to be at h4 faster than black can get to f6.
Similarly, white could reach b5 only from c4 if black cannot go to a5 or b5 in time. But a5 is not good enough when white has the move because then white has the necessary tempi to reach h4 ahead of black to f6. Therefor, c4 and b5 are 'related' squares, and have the equivalent effect as opposition.
Going a step further, the squares couples b3-a7, c3-b7 and d3 - c7 are 'related square' couples. Whoever enters one of these first has to give up 'opposition' if the other one can reach the 'related' square.
Going one more step further, b2-a8, c2-b8, and d2 c8 are 'related' squares. More generally spoken (and assuming that the tempo battle towards h4/f6 is still in balance) the rectangles' b2-d3' and 'a8-c7' are 'related. They are called the 'primary domain'. Whoever enters that domain first is bound to give up opposition.
White can win here with the following sequence: 1.Kb1 (stays out of the primary domain) Kb7 (follows and keeps the squares on 8th rank free to be able to occupy them if white moves to the second rank) 2.Kc1 Kc7 (he has to follow towards f6) 3.Kd1 Kd7 4.Kc2! Kc8 (black cannot reach b8) 5.Kd2! (occupies the related square) Kd7 6.Kc3 Kc7 (he has to follow) 7.Kd3! and wins because blackhas to leave the related square, and cannot prevent that white will access either b5 or be fast enough to h4.
EDIT: it is probably too abstract (and hopefully without too many mistakes) but I hope it at least illustrates the ideas.