5.- INVENTARIO DE PUNTOS DE AGUA
7.2.- FUNCIONAMIENTO HIDROGEOLÓGICO: PIEZOMETRÍA
The books generally tend to exaggerate the value of a .ft. center as such. If a .ft. center really hampers the enemy pieces, it is advantageous; otherwise not. Things that count against a .ft. center are: (a) ample maneuvering space for enemy pieces, even though on a wing; (b) a completely open file, which at any rate means freedom for � s; and (c) exchanges of pieces, especially minor pieces. Real control of the center is always advantageous, e.g., 4':)s posted there and not vulnerable to .ft. s. But a .ft. center does not always guarantee such control; all one can say is that it usually helps.
Much of the talk about "attacking the center" or "challenging in the center" is claptrap, in the sense that the main motive of such moves in the opening (e.g., ... c5, very often) is not understood; it is simply to make provision for developing .§s. If .§s can develop otherwise, such moves are often unnecessary.
This 70-mover from the Australian Correspondence Championship further illus trates how the value of a .ft. center can be almost nullified. As a game, its length is excused by its sheer excellence. Rarely does one see a 70-mover entirely free from obvious errors.
K. Ozols-H. Klass Catalan Opening (in effect)
1. c4 Nf6
2. g3 e6
3. Bg2 d5
4. Nf3 dxc4
A move that forces the opponent's Yf1 out is seldom bad. Watch how this little disability always mars White's position a little. This is not to say that White's game is inferior-just that there is "a little rift within the lute" to give Black consolation in a rather backward position.
5. Qa4t Bd7
6. Qxc4 Nc6
An idea favored by the American Mas ter Kevitz-in place of the usual ... Bc6. With "crude development," Black may have bet ter chances of harrying White's exposed YfJ.
7. d4
Making it a "Catalan" (constituted by the moves d4, c4, and g3, etc.).
7. ... Be7
8. a3 b5!
The crisis. If Black permitted b4 with out a blow, White's command of space in the center and one wing, taken together, might give White a decisive advantage. In stead, Black himself takes the initiative on the Yfy-side. If 9. Q3b5, ... Nxd4 10. Qs4 Bc6! and Black has sufficient freedom.
9. Qd3 b4!
Black is now saddled with the respon sibility of playing for ... c5 to eliminate a weakness that might be fatal. But he knows he can enforce it. Meanwhile, he has gained his objective-namely space, terrain, or fresh air, a frequent strategical motif in top-line chess.
10. a4 Rc8
The first step. Incidentally, Black in vites 77. Qg6?, when ... NbB would be a sound .ft. offer. [Ed. Note: Purdy is referring to
12. Q3a7 c5!} 1 1. Nbd2 12. b3 13. Bb2 Na5 c5 Bc6
14. 0-0 0-0
15. Racl Qb6
16. e4 Rfd8
As yet White's ft center consists of the e- ft only, since the d- ft can be liquidated whenever Black chooses. And the e- ft , though it does a vital job in guarding d5, is a target for pieces. White can seek only to hold the position. Black has the initiative. Note that conditions (a) and (b) are both satisfied-inasmuch as the c-file can be opened any time either side chooses. The one thing favoring a ft center is that all the pieces remain on the board.
17. Rfd1 Bb7
18. h3 h6
White's h3 was on compulsion. White must move his ¥/1, and wishes to continue defending the b- .ft. to avoid tying his <tl. Black's ... h6 was a far-sighted provision of sanctuary for his � against check on the back rank, made at a moment when the time factor is not vital-White being unable to do anything much.
19. Qe3 Ba6!
20. Rc2 c4!
This leaves White in undisputed pos session of the ideal ft center ( .ft.s on e4 and d4), but Black gains a passed ft on the ¥11- side and additional maneuvering space there; also, he forces some exchanges. The remote passed .ft. of course is the main factor. 21. bxc4 22. Nxc4 23. Rxc4 24. Rc1 25. Nd2 26. Nb3 27. Qxcl 28. f3! 29. Kh2 30. Nxa5! Nxc4 Rxc4 Bxc4 Ba6 Rc8 Rxclt Bb7 a5 Bc6!
A resource not available had White played Qs3 on Move 28 to protect his e- ft .
Of course 30. Qg l ? is too cramping. Note that White, not Black, is in danger of cramp.
30. ... Bxa4 3 1. Qc8t Kh7 See note to 18th. 32. Nc4 33. Qxc6 34. Ne5 Qc6 Bxc6 Bb5!
Fine play. White has no time to take the f- ft , because then ... Nd7-b6-a4, seeming a slow maneuver, cannot be stopped and would force White to yield his ¥/1-..Q. for the passed ft . White's next move looks fair enough. Who would dream that it could bring him into serious trouble?
35. f4 Kg8
It looks now as though White should have no difficulty at all in drawing by sim ply developing his �. However, it is not easy. Ozols probably looked at such lines as 36. Kgl Ne8! 3Z Kf2 (not 3Z Bf! Bxfl 38. Kxfl Nd6 39. Nc6 Kj8. For if then 40. Nxb4, Black wins two fts for one. Or if 40. e5, ... Nc4 wins off hand.) Nd6 38. Ke3,f6!
From this it appears that White had not yet quite realized on Move 35 that his posi tion contained the seeds of danger. He should at once have started "developing" by 35. Kgl! to be followed by Bfl, surely drawing. Probably Ozols was playing to the score-that old tempter-and fishing for com plications rather than equality. He now plays the move evidently prepared by his 35th; it is to open up for his As. It also gives him a passed ft , but, being in the center instead
of remote, a vulnerable one. 36. d5 exd5 37. exd5 Bc5! 38. Bf3 Ne8! 39. Kg2 f6 40. Nc6 Nd6 41. Na5 Bb6 42. Nb3 Kf7 43. g4 Ba4! And if 44. Nd2 ?, .. .Be3. 44. Bdl Nc4 45. Bel Ke7
Very elegantly, Black carries out the procedure of "changing the blockaders." The W will be able to blockade and assail the .ft. simultaneously, which the l£'1 can't. Black's passed .ft. is too remote for White to reciprocate. 46. g5 47. Na5 48. gxh6 49. Nb3 Kd6 Bb5! gxh6 Be3!
Before winning the .ft. Black forces an exchange, reducing White's drawing chanc es. Two checking lis can be very annoying to a player trying to win.
50. Kf3 Bxcl 51. Nxcl Kxd5 52. Bc2 Nd6 53. Kg4 Be8 54. Bb3t Kd4 55. f5 Nc4 56. Kf4 Nd2 57. Be6 Bh5! 58. Na2 b3 59. Nb4 Be8!
The li, having got the .ft. a step fur ther, resumes its all-purposes defensive post. Not 59 ... b2 60. Ba2 b7=Q. 67. Bxb7 Nxb7
because of 62. Nc6ffollowed by ... Ne7 and ... NgB, making the win an arduous business at best.
60. Bxb3 Nxb3
Now comes the last phase: turning the piece plus to account. It still needs care, with so few .ft.s left. White's W must be forced away from its f- .ft. .
61. Nc2t Kc5 62. Ne3 Bh5 63. Nfl Nd4 64. Ke4 Ne2! 65. Ne3 Nc3t 66. Kd3 Nd5 67. Nfl Bf3! 68. h4 Bg2 69. Ng3 Kd6 70. Kd4 Ne7! 71. Resigns
After 77. h5, ... Bc6 and it's zugzwang, the
great bugbear of ltls and Ws who, if al lowed to refrain from moving, could often laugh superior foes to scorn-highly benefi cial to the facial muscles.
The game is a fine example of sus tained accuracy by Klass combined with strategy of a high order. Going through the longer games of the Botvinnik-Bronstein match, could you match this one for excel lence? Probably not. This exemplifies the truth about correspondence chess: the play ers may not be so good, but the chess is often better.
COMBINATION VERSUS PLANNING
Ortvin Sarapu, champion of New Zealand and joint champion of Australasia for 1952, wrote a most helpful series in the New Zealand Chessplayer entitled, "Ortvin Sarapu Coaches."
The July 1953 issue contains No. 4 of the series. Here Sarapu mentions a system which he credits to the famous Soviet grandmaster Levenfish, also famous as a writer and analyst.
It is a system for evaluating a position: simply compare each white piece with its opposite number in the Black camp. With the permission of the NZ. C.P. we crib the article holus-bolus.
(Sarapu takes over ... ) Judgment
"First we examine the situation for ma terial.
"White has Rook for Bishop and pawn, but Black has two powerful Bishops. So material is about equal.
"Second, we come to the more impor tant part-to judge the positional advan tages and disadvantages.
"The system of comparing every piece and pawn individually with its rival comes, as I know, from old grandmaster Levenfish, who drew a match 5-5 with Botvinnik in
1937.
"The system's advantages are that it helps you to get a correct or nearly correct understanding of the position, to judge which player has the better chances. It enables
avoidance of obvious blunders and gives direction to your efforts to discover what you must do to improve your position.
"Its disadvantage is mainly that you have a limited ration of time on your clock, but you can do a lot of 'work' during the opponent's thinking time.
Kings
"We start with the Kings. It is clear that the white King is dangerously placed. He has no move and is "x-rayed" by the black Queen's Bishop. He is guarded mainly by two pawns.
"On the contrary, the black King is safe, far from any threats. An endgame advantage for Black is that his King is closer to the center.
Queens
"The white Queen protects the weak c pawn and the weak square £2, but she pins the Knight. The Queen cannot move much without allowing ... Nj2f or ... Nxc3. There fore she is tied to defensive tasks.
"Black's Queen protects her weak f pawn and is unguarded; also she is indi rectly attacked by the white Queen. But she can move and improve her position with out incurring disadvantage.
"Our 'diagnosis': both passively placed. one of them. This is the only, but strong, threat White has.
White King's Rook and Black Rook "The King's Rook has pressure on the f-pawn, but is pinned to defense of square f2, so his mobility is limited.
"The black Rook is actively placed, close to the center, has pressure on White's weak c-pawn and on the weak King-side, but is unguarded.
"We give the black Rook superiority. White Queen's Rook and Black's Queen's Bishop, King's Bishop Pawn
"The Rook is undeveloped, can be de veloped in one move, but remains passive, and Rd1 will lose the Exchange after ... Rxd1. "Black's Queen's Bishop controls two center squares and 'x-rays' White's King. Its power will increase when the black Knight moves. The f-pawn is backward and under pressure, also it would be hard to improve its position.
"At present the Bishop is stronger than the white Queen's Rook: another plus for Black.
The Other Two Bishops
"The black King's Bishop controls the long open diagonal and bars the white King from moving. In cooperation with the Knight, it has strong pressure on White's weak f2.
"The white Bishop has merely defen sive duty in protecting the c-pawn, is un guarded, but controls two center squares and supports e5 for the white Knight.
"The black King's Bishop is the supe rior piece.
Knights
"The white Knight is unguarded, but it has a protected square on e5 from which it would attack simultaneously the adverse Rook and Bishop, and exchange against
"The black Knight is pinned and is in the way of the Queen's Bishop. It is pro tected, in the center, and has pressure on f2,
g3, and c3.
"As the white Knight has a good threat, we can say it has some advantage over its rival . . . unless the black Knight has a threat to balance.
The Pawns
"We compare a-pawn versus a-pawn, e-pawn versus e-pawn, and so on.
"The a-pawns are about evenly placed, protected, but not under pressure.
"The b-pawns are the same, only that White's is protected by the weak c-pawn and can become weak itself.
"The c-pawns: White's pawn is twice attacked, by Rook and Knight, and just protected-by the valuable Queen and the Bishop. It is a clear weakness in White's game. (An inexperienced player as Black would go after it, but wrongly in this case.) "g-pawns: The white pawn is semi pinned by the Queen's Bishop. Its value is in covering its King. The black g-pawn is well advanced and very dangerous for White. It is threatening to advance and break the white King's position by attack ing f2 and h2. Also, by advancing this pawn to g3 Black can play his Queen to h4 with mating threats. So there is one strong threat against White's possible Ne5.
"Now, last, the h-pawns: Black's pawn is advanced, and also is threatening to break White's King's position in two moves by going to h4 and h3. While White's g-pawn is semi-pinned, that is another dangerous threat against White. But it is two moves long, during which White would have time to play Ne5 and Nxc6. The white h-pawn is merely protecting the King from frontal checks and barring enemy occupation of
g3. It can be attacked by the black g-pawn. So his h-pawn is a decided weakness in White's position.
"By means of all this comparing, we are able to judge the position as it is at present on the board.
"Black has a big advantage.
"Further, we know where his advan tage lies: it is on the King-side, particularly against White's King. Black's pieces 'aim' in this direction; so it would be wrong to con centrate against White's weak c-pawn. Black must do something on the King-side, other wise his advantage would slowly disappear after Ne5!
Planning
"As we know White's threat and one of Black's threats, we (as Black) have to find which weakness on White's King-side can be exploited successfully and in less time than White's threat takes for its execution.
"Weaknesses, we know, are on White's f2, g2, and h2.
"To use f2 we need more pressure on it, so we make the attempt 1 ... g3, which also threatens White's h-pawn and ... Qh4 and mate on h2.
"If White plays 2. Ne5, ... Q!t4 3. h3 QJh3f 4. gxh3 Nf2t 5. Kgl Nxh3#.
"We can disregard the threat of 1 ... h4, which gives White ample time to defend. For instance, 2. Ne5 h3 3. Nxc6 and White has avoided a quick loss.
"So attack on White's g-pawn is too slow."
(Sarapu evidently intended to mention the objection to 1 ... g3. We leave it to our readers, for they would have to see it in actual play.)
Against White's h-Pawn
"As we know, the white g-pawn is semi pinned. Therefore perhaps we can play 7 ... Rh3, with the threat of mate or win of the
Queen by ... Ng3f, as gxh3 cannot be played because of ... Ng3f and mate.
"But the catch here is that White will make room for his King by 2. Bd4, to play Kgl after ... Ng3f.
"We could continue the attack by 2 ... g3! 3. Rf4 (of course 3. gxh3 Nj2t 4. Kgl Nxh3#) Rxh2t 4. Kgl Nj2! 5. Rxf2 ( 5. QJe7 Rhl#) gxj2f 6. Kxj2 Rxg2f with a winning attack. But it is too long again.
"There must be something better. Only the white h-pawn and the black Knight are in the way.
"How can we remove them?
"We see it all now: 1. •• Ng3t!! 2. hxg3
Qh4t!! 3. gxh4 Rh3#.
"White can of course decline to die so beautifully by playing 2. QJg3, but Black still wins with ease.
"Combinations do not 'come to us.' We have to find them. When we know exactly where the weaknesses are in a posi tion, we have covered the most difficult part. The rest is what is generally called 'routine,' but care is always required. There is no excuse for carelessness."
(End of Sarapu's article.) Commentary
There is a great deal to be said for Levenfish's form of reconnaissance from a positional viewpoint. As Sarapu says, it can usually be carried out during your oppo nent's move-a far better way of using the time than speculating on possible moves, of which he can play only one. Moreover, although it cannot give a precise estimate of a position, nevertheless it forces you to observe many things you could easily miss by reconnoitering less methodically. I think many readers will have occasion to bless Sarapu for drawing their attention to the system.
(article diagram repeated)
Black to move
Now note that I said, "from a posi tional viewpoint." Look at the diagram again, reprinted on this page. You already know the combination that wins for Black a very nice sacrifice of� and 4). It is based on the white �'s lack of squares: one safe check must be mate-a type of "net." Just how much is the combination based on the positional valuation, or upon Black's posi tional superiority as estimated by that valu ation? I say that it has very little connection therewith. For supposing we greatly im prove White's position in various ways, and make it like the next diagram.
(Hypothetical diagram)
Black to move
Here we have eliminated White's glar ing weakness at c3; we have transferred his undeveloped § to the positionally magnifi cent square e2, where it reinforces the pres-
sure on the black 4::1; and we have advanced the other § to f4 so that it threatens Rxe4.
If we now apply the Levenfish system, we shall at least be in grave doubt as to who, on the whole, comes out on the credit side. No longer are the black § and 4::1 bearing on a weak ft , nor are any white pieces tied to its defense; no longer can we claim that Black's �-.il must be rated above White's �- §-always remember, we are not sup posed to have seen any combination yet, for if we had, the reconnaissance would be unnecessary. We can only judge on purely general grounds. On those grounds, how could we place Black on the credit side? Indeed, if it were White's move he would win material forthwith, and Black might begin casting about desperately for some way to save his 4), and consider the sorry resource .. .j5-ifhe didn't see the combina tion.
Yes, the combination is still on, and is even stronger now! There are several other changes we might have made in the posi tion without eliminating it, just as there are numerous possible ways of ruling it out e.g., in the first diagram, place the white 4::1 on e2, and then, although you could not say the 4::1 was as well placed in a vague, posi tional sense as on c4, yet it would be nearer its own � and would prevent Black from making a crushing assault; and Bd4 would become a good defensive threat.
In short, we can improve White's game "positionally" and make him lose more quickly: we can make it "worse" and give him a fighting chance! No kidding? No, no kidding!
Why did I say "even stronger"? Be cause after 1 ... Ng3f 2. Q;cg3 Rxg3 Black has a § en prise, and of course White cannot take Black's � because of ... Bxg2#. So, for the combination, White's § is worse placed when well developed (on e2) than away in a corner doing nothing. Such paradoxes are
typical of combinations in general. General principles count for nothing when there is a way for one player to force certain moves by his opponent. By a combination, as Emanuel Lasker says, in effect, you may twist credits into debits and debits into cred its. Looked at positionally, combinations are sheer "Alice in Wonderland." They up set the logical side of chess-using "logical" in the popular, narrow sense-with romance.