2. Capítulo: La transformación del hábitat, con los proyectos de desarrollo
2.3 Proyecto hidroeléctrico Ituango
Accurately played. After 18...e5 19. a4! b4 20.Ad3 g6 21.Ae3 the white bishops exert unpleasant pressure on the black queenside.
19. #e2 exd5 20.1xd5
20...^f6
This seems fine, although it would be more active to play 20...^b6 i n or- der to leave the f6 square for the queen. In positions where the central structure has been completely removed it is the relative activity of the pieces which often decides the evaluation.
21.1d3#c7 22. g3 A c 5 23. A e 3 A x e 3 24.1xe3lfe8 25.1dl h6 26. a3 Hxe3 27. #xe3
White is very slightly better thanks to his bishop vs. knight advantage.
27...^g4 28.#e4^e5 29.1d5^c4
A difficult decision. After 2 9 . . . ^ c 4 White is achieving the simplifications he wants, although attempting to an- chor the knight with 29...f6 is hardly attractive either while the white bishop remains o n the board.
P A R T 2. P r i n c i p l e s A n d Essential T h e o r y
30.#d4le8 31.1c5 £>d2!
The tactical justification behind 30...He8, but it leads to exchanges to a favourable endgame for White.
32.1xc7 ^f3+ 33.*g2^xd4 34.1d7!
34...^c6
If the knight moves to another square then Hd7-d6 is hard to meet.
35. Hd6
Forcing an endgame with some chances to play for a win.
35...He6 36. Hxe6 fxe6
Let us summarize the endgame which has arisen.
White has a bishop against a knight which, unless some particular feature of the pawn structure suggests otherwise, should be an advantage. A l l things being equal, the bishop is simply a slightly bet- ter piece. We can see the black queenside pawns look slightly shaky, and there is a potential weakness on e6. Also, the white king can come to the center very quickly.
Again it is a question of degree. White is certainly better, but is Black's situation bad enough for her to be lost?
37. * f 3 * f 7 38. * e 4 * e 7
White has secured an advantage in king activity, but the black e6-pawn and knight coordinate well to prevent any further penetration. N o w what should White target? It is difficult to target the e6-pawn, and the king cannot break through to the kingside.
Lesson 9. B a c k to R e a l i t y — O t h e r M i n o r - P i e c e Endgames
Cleverly exploiting the weakness on a6.
3 9 . . . ^ a 7
The alternative 39...bxa4 was not attractive; after 40.Axa6 the black a4- pawn is chronically weak. It can eas- ily be attacked by the bishop from b5, and there is no longer any issue of the white king being unable to penetrate to the pawn. It is also very difficult for the black knight to defend this pawn.
Note it was vital that White acted quickly with 39.a4!, for if he had pon- dered and allowed Black the extra move ...*e7-d6 then Black would solve all the problems. Pushing a3-a4 would lose all its impact as Black could respond ...b5xa4, and after A f l x a 6 simply play ...<4>d6-c5!
After 39...^a7 though, the black knight is frozen on this square for the immediate future.
40.axb5 axb5
The pawn ending with 40...^xb5 41. A x b 5 axb5 is lost for Black; White's king position is too strong and the black b-pawn is too weak. For example, 42. * e 5 * d 7 7.f4 (it is simplest to leave the white pawn on b2 for now, partly to keep reserve tempi and also because in some positions where White penetrates the kingside Black may be able to cap- ture the white b-pawn and get coun- terplay) 42...*e7 43.h4 g6 44.g4 * d 7 45.g5 hxg5 46.hxg5 * e 7 47.b4 and White penetrates to f6 or d6, winning the game.
4U4
White actually would like to remove the weak looking e6-pawn with f4-f5, in order to gain access the black kingside pawns.
4 1 . . . * d 6 42. A d 3
White believes that the black king stands sufficiently well on d6 and that it is worth delaying f4-f5 (which is also possible here, but White has to reckon with the reply 42.f5 e5!?) i n order to force the black king to move to a less ac- tive square.
4 2 . . . * d 7
The only try to keep the king on d6 would be 42...b4, which also frees the black <£}a7. O f course we already know that creating far advanced pawns as the defender is rarely a good idea. In- deed, after 4 3 . * d 4 ^ c 6 + 4 4 . * c 4 e5!? 45.Ae4 Black is i n big trouble.
P A R T 2. P r i n c i p l e s A n d Essential T h e o r y
44. A f l * d 7 45. f5!
White had a rethink and decided he wanted the bishop on f 1 and now finally the key advance f4-f5 comes.
45...*d6
45...exf5+ 46.(4>xf5 speeds up the
process for White as his king gains ac- cess to g6 right away.
46. fre6 *xe6 47. A h 3 + * d 6 48. * f 5
48...g5
Black could also defend passively with 48...*e7 4 9 . * g 6 * f 8 5 0 . A f l ! b4 (what else? If Black plays 50...*g8 then simply 5 1 . ^ f 5 coming across to w i n the b-pawn) 51.*f5 * f 7 52.*e5 * e 7 5 3 . * d 5 and Black loses the b-pawn.
49. *g6
White wins a pawn.
49...*e7 50. *xh6 * f 6 51. A d 7 !
Black knight is dominated...and something is happening on b5
Completely dominating the <£}a7.
51...*e7 52.Axb5!
After 52.Ag4 * f 6 53.h4 Black can fight on. Although the position is prob- ably lost there is still some work to do.
L e s s o n 9. B a c k to R e a l i t y — O t h e r M i n o r - P i e c e Endgames
With 52.itxb5! the game is immediately finished as the black knight is complete- ly overloaded. 52...^xb5 53. *xg5 * f 7 54. * h 6 ^ d 4 55. g4^f3 56. h3 *f6 57. b4
Pawns are too strong
Black resigns.
S U M M A R Y
> In the absence of immediate tactical considerations, endgame with bishops of the same color can, typically, be evaluated in terms of pawn structure and king activity.
> When trying to exploit an extra pawn advantage, same-colored bishop end- games would rank highly on a list of desirable situations for the stronger side. A l l things being equal, an extra pawn will usually be decisive.
> Bishop vs. knight situations are more difficult to assess (we will look at more examples i n the exercises). The usual universal factors apply, but pawn structure be- comes more critical to the assessment. The more asymmetrical and non-compact the pawn structure is, the more the bishop's advantage grows, because it is a long- range piece which can function on both wings simultaneously.
T H E O R E T I C A L N O T E S
We will take a look at some instruc- tive theoretical positions from the end- game of bishop and pawn vs. bishop, showing the battle for key diagonals.
Consider this position which will demonstrate defense is always hopeless without a defending king:
P A R T 2. P r i n c i p l e s A n d Essential T h e o r y
The black bishop must be forced from the d8-h4 diagonal so that the pawn can safely step to d8.
1. A b 6 A h 4
2. A d 8
The only chance for a defense now is to relocate the bishop to the a5-d8 diagonal. This is possible here because the d8 square is occupied by the white bishop, preventing the pawn from pro- moting.
2 . . . A e l 3. JLf6
Preventing the black bishop from re- turning to the h4-d8 diagonal.
3...J§La.5
4. A e 5 !
However, on this side of the pawn White's king can support his bishop coming to c7.
4...Ab6 5 . A c 7
A much more effective way to drive the bishop from its protection of d8. Now Black has no time to switch diago- nals and d7-d8=# cannot be stopped.
If we move the pawn further back it is the same story.
This is like having to win the previous position three times. White must safely get his pawn past the three dark squares in its path (d4, d6 and finally d8).
Obviously i n real terms Black would be very likely to draw this, as he would likely reach d7 with his king. Without his king the pawn cannot be stopped as Black will continually be driven away from diagonals and the white pawn will gradually advance.
Let us take a real game situation, and see how the defending king can assist i n the defense.
Lesson 9. B a c k to R e a l i t y - O t h e r M i n o r - P i e c e Endgames
Averbakh, 1983
White to play
Can he win this position?
Note that although the white pawn is only on the sixth rank, and i n our initial example the pawn was on the seventh rank, that it is not the correct way to dif- ferentiate between the positions. What we should be thinking is that in both cas- es the pawn has one important square to cross, here it is d7.
1. A h 5 !
This move is automatic. If White plays any other move Black will play <4>f8-e8-d8. H o w would we move the king from d8 to queen our pawn? It would be impossible. Even i f this posi- tion were a draw anyway we must pre- vent the simplest defense.
l . . . A h 3
2. * e 5 ! ?
The direct approach with 2. A g6 A d7! 3.Af5 is not effective, simplest for Black
is 3...*e8! (but not 3...Axf5?? 4 . * x f 5 and the pawn endgame is lost) and the pawn endgame is drawn (if White avoids the exchange then of course the black king reaches d8 with an easy draw).
With 2.*e5!? White is planning to reposition his king on the c7 square first and only then try to drive away Black's bishop from the key diagonals.
2 . . . A d 7
3. * d 5 A h 3 ? ?
Black continues to wait but this is in fact a losing move. We will see why and then see what Black should play i n - stead.
4. * c 6 ! A f 5 5. * c 7
The problem for Black is that his king is really doing nothing to aid the defense. White will simply maneuver his bishop to d7 and position the bishop on the h3-c8 diagonal. Black will be forced to relocate to the a4-e8 diagonal, then
P A R T 2. P r i n c i p l e s A n d Essential T h e o r y
the bishop comes to c6 with devastating effect.
5 . . . A h 3
6. A f 3 A f 5
7. A c 6
Following the normal procedure and coming to d7 when in fact it would be quicker to play 7. A b 7 followed by 8. A c 8 forcing d6-d7. 7...Ag4 8. A d 7 Ae2 9. A h 3 A b 5 10. Ag2 A a 4 11. A c 6
A n d the pawn will shortly queen. White wins.
Returning to the position after 3 . * d 5 we will now look at the correct defensive procedure:
3...*g7!
If the white king is heading for c7, the black king is heading for c5! This is actually a very strong square for the de- fending king. It prevents White's idea of playing A c 6 and it also prevents the idea of A c 8 (because Black could sim- ply exchange and capture on d6 with his king).
4. * c 5 *f6 5. * b 6 * e 5
6. * c 7 A h 3
7. Ae2
White begins his standard plan to bring the bishop to d7, but this time Black is ready for it.
7 . . . * d 5 ! 8. A b 5
As mentioned previously, with the d6-pawn attacked, the plan of A a 6 - c 8 is no longer valid.
Lesson 9. B a c k to R e a l i t y - O t h e r M i n o r - P i e c e Endgames
8...*c5
If Black cannot achieve a draw in a simple way by putting his king on a safe square in the pawn's path, then this is the second line of defense, taking oppo- sition behind the attacking king.
9.Ad7 A f l
Switching diagonals.
10.Ag4 A b 5
Now we see White's problem — the black bishop will simply make moves on the a4-e8 diagonal, alternating between a4, b5 and e8. White cannot play his bishop to c6 anymore, so his only way to remove the bishop from the diagonal is via A d 7 . This blocks the pawn, and gives Black time to switch to the h3-c8 diagonal, on which it also has plenty of squares to wait.
H . A f 5 A a 4
12. A h 3 A b 5 13.
Ad7
A e 214.Ae8 A g 4
It is clear that White cannot make any progress.
If we shift the whole position to the left by one file, can Black still hold?
Let's find out. First of all White will force the black bishop onto the shorter of the two defensive diagonals (a5-d8).
1. A c 7
Ad2
2.
A g 3 A a 5This time Black has fewer squares on the short diagonal, but just enough.
P A R T 2. P r i n c i p l e s A n d Essential T h e o r y
3AfZ A d 8 4 . A e 3 A a 5 5 . A g 5 A b 6
Black has just enough squares to draw.
In general a four-square diagonal is enough for the defending bishop; there- fore if both defending diagonals are four or more squares then defense is secured (if the kings are in rear opposition like this of course!).
In this diagram we can see that one defensive diagonal, that of c8-h3, is very long, six squares. The other defensive diagonal, a6-c8, is very short, only three squares (remember the rules, three is less than four!). This means the defender is in serious danger of losing the game and actually here he is just dead lost.
1. A g 2 A f 5 2. A b 7 A g 4 3. A c 8
Driving the bishop to the short d i - agonal.
3... j§Le2 4. A h 3 A a 6 5.Ag2!
Black is devoid of waiting moves with his bishop and if he moves his king then our old friend A b 7 will arrive. Black is lost.
Lesson 10
Exercises!
Before we move into Part 3 of the book, it is the turn of you, the reader, to do some work! A l l of the exercises are related, at least partially, to material we have cov- ered in Part 1 and Part 2 of the book. They are deliberately placed here, and rather mixed up, so the reader has no free inkling of which material they are relying upon.
I would advise the reader to spend at least 15 minutes on each exercise (some of the simpler ones can be solved i n much less time so i f you are completely sure you have the correct solution then stopping is fine). If you cannot solve an exercise i n this time, then read the solution in its entirety and revisit the relevant lesson on which the exercise was based.
It is important that afterward, unless you solved the exercise flawlessly yourself that you:
Return to the exercise and repeat it, even though this time you know the solu- tion.
Try to see everything in your head this second time, to show yourself that you can now visualize everything that was required to solve the exercise.
When reading the solution to Exercise 13, you will be asked a further question. Please solve this in the same way as the other exercises and find the solution i n the section 6Follow-up Solutions'.
P A R T 2. P r i n c i p l e s A n d Essential T h e o r y
Exercise 1
White to play
Suggest a plan for White based on re- stricting the black A h 5 .
Exercise 2
White to play
F i n d the strongest continuation.
Exercise 3
White to play
How do you assess this position? How do you see the game playing out?
Does Black have any chances to hold the game?
Exercise 4
Black to play
Evaluate the endgame which results after l . . . A e 5 +
Lesson 10. Exercises!
Exercise 5
White to play
Assess White's winning chances. Find the strongest continuation for White.
Exercise 6
White to play
Assess the position and suggest a plan for White.
Exercise 7
White to play
Assess the position: does Black have winning chances?
In the game White played the move 1 .b4 to exchange a pair of pawns and re- duce the material.
What do you think of this move?
Exercise 8
White to play
Assess the knight endgame which could result from l . B x b 8 + .
In the game White chose the move l . H e l . What do you think of this deci- sion?
P A R T 2. P r i n c i p l e s A n d Essential T h e o r y
Exercise 9
Exercise 11
White to play White to play
In the game White avoided the ex-
change of rooks and drew easily, but was how? the exchange l.Hxf6 losing?
Exercise 10
Can he save the game and if so, then
Black to play
C a n he save the game?
Exercise 12
White to play.
L e s s o n 10. Exercises!
Exercise 13
Exercise 15
Black to play White to play
C a n he draw?
Exercise 14
White to play.
The black king is cut and the pawn is on the fifth rank. Is White winning?
Is he winning and if so, how? What positions is he aiming for? Is the result changed i f Black is on the move?
Exercise 16
White to play
Assess the position. What should White play?