how to play chess endgames book

188 How TO PLAY CHESS ENDGAMES
If White had realized in time that there was a
possible fortress, he would surely have chosen
I @g3. But after l...@e6 2 f5+ Black can draw
by 2 ... @xf5, since he will reach a similar fortress
to the one in the game. But note that
2 ... @d7? 3 @xg4 tbxd6 most probably loses,
even after 4 .i.f8?! (D) (4 .i.xd6 is a clear win),
owing to the bishop's superiority; e.g.:
into play: 14 ... @f8 15 g6+-) 12g5 tbc413 g6+
@g8 14 .i.d4 b2 15 f6 -t-.
l ...@xf42d8~
2 .i.f8!? at this point would definitely force
Black to play precisely, but should bring no real
advantage. 2 ... @f5 3 il..xg7 h5 (3 ... @e6 4 @g3
@xd7 5 <Bxg4 tbd6 6 b6 tbc4 7 .i.d4 @c6 =) 4
@g3 @g5 5 .i.e5 h4+ 6 <Bh2 h3 7 g3 @f5 8 il..c7
@e4=.
2 ... tbxd8 3 hd8 gS 4 il..c7+ WfS 5 @g3 hS 6
@f2 h4 7 @e3 g3 8 @f3 g4+ 9 @e3 @e610 @f4
h3 11 r,t;xg3 hxg2 12 @xg2 @dS 13 @g3 @cS
14 b6 Wc6 15 'ittxg4 @d7 16 Wf4 @c8 1/2-1/z
A drawn outcome is practically forced.
Exercises (Solutions on page 324)
a) 4 ... lbxb5 5 Wh5!?@e8 (5 ... tbd6? 6 .i.xd6
-t-) 6.i.xg7 tbd6 (6 ... Wf77 .i.xh6 tbc3 8 g4 b5
9 g5 tbe4 10 @g4 +-) 7 g4 b5 8 @xh6 @f7 9
.i.e5 lbc4 10 .i.f4 b4 II g5 b3 12 g6+ @g8 13
.i.cl -t-.
b) 4 ... h5+5Wg5lbxb56@xh5@e87.i.xg7
@f7 8 .i.al !? (so that later on Black will not be
able to win a tempo for supporting his passed
pawns with ... tbc4) 8 ... tbd6 9 g4 b5 (D)
El 1.06 **/
White can prevent the creation of a
fortress in two ways. Find them.
10@g5 b4 ll Wf4 b3 (after ll...tbc8 12 g5
tbe7 13 @e4 b3 14 .i.b2 zugzwang will come
Ell.07 /**
How does Black force the draw?