Now the black king cannot get off the edge of the board.

With 12 d5, White opened lines against the black king.

In this case black king can't escape on c8 or e8.

Nxe5+, which drives the black king out, has been played.

Then she made the black king her target with 19 Rf3 and 20 g4.

Kg7 Kf9 it is safe for the black king to double back.

If this defense is used, the black king should be on the second rank.

For example, if the black king were on f6 instead, with White to move, 1.

Moreover, after 23 d6, lines of attack against the black king became available.

Rd6+ and the black king is kept out of play.