Friday, July 24, 2015

Reti's Tightrope Maneuver: Part 2

It's been nearly a week, and I assume your geometry should have improved after that math graded task. Which means it's time to look through the 3 puzzles I have issued y'all in the last challenge. Once again, Reti's tightrope maneuver is the motif that we will use in these puzzles.

Just don't look down (Image from Wiki)

All ready? If so, let's get started:

Adamson 1922
Position 1: White to move and draw

This one is simple enough if you remember Reti's Puzzle. All White needs to do is head towards both pawns at the same time by stepping first onto the b1-h7 diagonal followed by the a1-h8 diagonal. Sit back and see Reti's tightrope maneuver in action:

1. Kg6!

White prepares to execute the tightrope maneuver by approaching both pawns at the same time.

1... a4
2. Kf5 Kb6

2... a3 3. Ke6 and White's pawn promotes.

3. Ke5!

Reti's motif activated! White prepares to either step into the square of Black's pawn or escort his own pawn to promotion. And not 3. Ke4? a3 4. Kd5 a2 when White can no longer escort his pawn safely.

3... a3

Or 3... Kxc6 4. Kd4 entering the square.

4. Kd6 a2
5. c7 Kb7
6. Kd7
1/2-1/2

And White's pawn promotes.


Yates, Fredrick - Marshall, Frank James
Karlsbad 1929
Position 2: Black to move and draw

The position was reached in Yates - Marshall 1929, after White's 60th move. Black cannot catch White's pawn with the direct route 1... Kc2 because of White's first move advantage 2. f4. However, he can use the Reti tightrope maneuver and threaten to escort his pawn first, giving him much-needed tempi to catch up with White's pawn.

60... Kb2!

Once again, preparing to either step into the White pawn's square or escort the Black pawn. White must spend tempi getting rid of Black's pawn, giving Black time to catch the enemy pawn

61. Kxa4

Or 61. f4 a3 and Black's pawn promotes.

61... Kc3

Using the diagonal to step into the square. Draw.

62. f4 Kd4
1/2-1/2


NN
Source Unknown
Position 3: White to move and win

This position is slightly tricky. White appears to have the advantage since his king is closer to the pawns. However, Black has a drawing trick: If he can get his king to g8 or f8, he draws by sacrificing his pawn with ... h3! creating a drawn rook-pawn endgame. Hence, White must employ the Reti tightrope maneuver to shadow Black's king and get close to the pawns at the same time.

1. Kd3!

Reti's tightrope motif activated! White uses the b1-h7 diagonal to shadow Black's king and approach the pawns at the same time. On the other hand, blocking Black's king directly won't work: 1. Kc3? Kb5 2. Kd4 Kc6 3. Ke5 Kd7 4. Kf6 Ke8 5. Kg7 Ke7 6. Kg6 and now Black unleashes his trick: h3! 7. gxh3 Kf8 8. Kh7 Kf7 trapping White's king on the h-file and creating a drawn rook-pawn endgame.

1... Kb5
2. Ke4 Kc6
3. Kf5

Once again going straight for the pawn falls to the same trap: 3. Kf4? h3! 4. gxh3 Kd7 5. Kg5 Ke7 6. Kg6 Kf8 7. Kh7 Kf7 Draw.

3... h3

Or 3... Kd7 where White switches his attention to the Black pawn: 4. Kg4 Ke6 5. Kxh4 Kf5 6. Kh5 winning.

4. gxh3 Kd7
5. Kg6 Ke8
6. Kg7
1-0

Covering the critical squares needed for White's pawn to promote safely.

...

Simple, wasn't it? Through these series of puzzles you will be able to acquire a better understanding of how geometrical motifs are used in gameplay, sometimes turning what seems like defeats into miraculous draws!

Links:
Part 1: http://nushsblackknights.blogspot.com/2015/07/retis-tightrope-maneuver-part-1.html

Sources:
"Silman's Complete Endgame Course" by Jeremy Silman
"Rosen's Chess Endgame Training" by Bernd Rosen

Saturday, July 18, 2015

Reti's Tightrope Maneuver: Part 1

A chessboard consists of 64 squares. To the common man it might seem like amazingly boring terrain upon which to wage war. But to the chessplayer, knowledge of chessboard geometry-- especially with pieces involved-- can be an interesting element, and sometimes the factor that decides between a win or loss.

We have already touched on elements of the chessboard by talking about the long and short sides of the board in rook endgames. Today, we will look at another example of chess geometry in action: Reti's tightrope maneuver.

No, you don't need Ptolemy's Theorem or the cosine rule to work this out. Just a simple understanding of the diagonals and good king footwork will do. Take a look at the puzzle below, published by Richard Reti in 1921:

Reti, Richard
Kagans Neueste Schachnachrichten 1921
White to move and draw

At first glance, it seems that White's position is hopeless. His king is well out of the square of Black's pawn (see this Wiki article if you're not sure what that means) and has no way to catch it. On the other hand, Black's king is only two squares away from capturing White's pawn! So White should resign... or should he?

Take some time to look at the position, before scrolling down.
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Reti discovered that White could draw in this position, by exploiting the diagonal to go on a risky "tightrope" maneuver. Precision is needed here:

1. Kg7!

Black's king has to spend two tempi to capture the pawn, which is enough time for White to enter the square of the Black pawn. Thus, White can exploit the diagonal to get closer to both pawns at the same time.

1... h4

If 1... Kb6 2. Kf6 Kxc6 3. Kg5 White captures the pawn.

2. Kf6 Kb6

2... h3 and White just goes over to escort his pawn: 3. Ke7 h2 4. c7 Draw.

3. Ke5

The point of White's "tightrope" maneuver is to ether step into the square of Black's pawn, or escort his own pawn to promotion.

3... h3

Once again 3... Kxc6 allows White to get into the square of Black's pawn with 4. Kf4

It seems that Black's pawn cannot be stopped. Is it time for White to resign?

4. Kd6!

Of course not! White simply ignores Black's pawn and moves over to escort his own pawn.

4... h2
5. c7 Kb7
6. Kd7
1/2-1/2

And White's pawn cannot be stopped from promoting. Draw.


Amazing, isn't it? Reti's discover eventually became an important idea in king-pawn endgames, with the same motif being employed in many games and puzzle compositions.

Here I will leave 3 such puzzles for y'all as a challenge. Try using Reti's tightrope motif to solve them!

Position 1: White to move and draw

Position 2: Black to move and draw

Position 3: White to move and win

Once again, I will discuss the solutions next week. Have fun! (:

Sources:
"Silman's Complete Endgame Course" by Jeremy Silman
"Rosen's Chess Endgame Training" by Bernd Rosen
http://giphy.com/gifs/funny-fun-amazing-2U0vh8iE6ZYti

Saturday, July 11, 2015

Finding Order from Chaos

Chill guys, this isn't a lesson on entropy. But perhaps finding order from a complex position in a game of chess might be simpler than finding that chemistry worksheet from your bedroom desk.

It's probably below that Chinese workbook you haven't touched since last year

For today's article, we will look at a complicated game of mine from Chess.com. From this game, you will observe a tense struggle on the centre and kingside, with the position made incredibly fluid by the inaccuracies made by both sides. Fortunately, a final endgame mistake by my opponent allowed me to win the game.

Opponent vs Checkerboard 5
Correspondence Chess 2015

1. e4 c6
2. Nf3 d5
3. exd5 cxd5
4. Bb5+ Bd7
5. Qe2 Nf6
6. Ne5 Nc6
7. Nxd7 Qxd7
8. O-O a6
9. Bxc6 Qxc6
10. d4 e6
11. Bg5 Be7
12. c3 O-O
13. Nd2 Rfe8
14. Nf3 (D)

Position after 14. Nf3

Both sides have completed development. Here, the most striking features are the holes on e5, e4 and c4, as well as Black's pawn minority on the Queenside. I decided to exploit White's weak squares immediately:

14... Ne4

In post-game analysis I realized a better plan would be to start a queenside minority attack combined with exploitation of the weak squares: 14... b5 15. Ne5 Qb7 16. Rfc1 Ne4 17. Bxe7 Rxe7 18. f3 Nd6. (D)

Position after 18... Nd6

Although White has a strong knight on e5, Black threatens moves like ... Nc4 and ... Rc7 exchanging off the knights and supporting the advance of the queenside pawns. For example, after 19. Rc2 Rc7 20. Rac1 Nc4 Black can start rolling his pawns forward and exchange on c3 to give White a backward pawn.

15. Bxe7 Rxe7
16. Ne5 Qb6
17. f3 Nd6
18. f4!?

White weakens the e4 square to generate a kingside attack.

18... Rc8
19. Ng4 Nc4
20. Rab1 Qc7
21. Ne5 Nd6

After 21... Nxe5 22. dxe5 White can push g4 followed by f5, generating very strong threats that I felt was best avoided.

22. Qf3 Ne4 (D)

Position after 22... Ne4

23. Rbd1

White could have kept up the pressure with 23. f5! f6 (23... exf5? 24. Qxf5 and I'm left with a very weak isolated pawn on d5.) 24. Ng4 e5 25. dxe5 fxe5 26. Rbd1 Rd8 27. f6. Here it appears that Black's position will crumble, but he has a saving move: 27... Rf7! 28. Qf5 Nxf6 29. Nxe5 Re7 {White still exerts significant pressure, but at least I can find enough counterplay with the open e-file and a future threat of pushing d5.

23... f6?!

With this move I made the position very complicated. My intent was to chase away the knight and prepare for an eventual e5 break; however, this creates a weak pawn on e6 as well as another weakness on d5 should I eventually push e5. Perhaps I could have expanded on the queenside with 23... b5 (the threat here is ...a5 followed by ...b4 creating a weakness along the c-file) 24. f5 f6 25. Ng4 e5 with a similar line to a previous variation.

24. Ng4 Rf8?!

Another inaccuracy; should the f-file be opened White has the threat of Qxf8#. 24... Qd6 {reinforcing the centre was better.

25. Nf2 Nd6

My earlier mistake would be proven after 25... Nxf2 26. Rxf2 and now I cannot push 26... e5? due to 27. fxe5 fxe5?? 28. Qxf8#

26. Rfe1 Rfe8
27. Rd2 Nc4
28. Rde2 (D)

Position after 28. Rde2

28... Qd6?!

Surprisingly my position was actually ok after 28... Nd6 (guarding against the threat of 29. f5) 29. Nd3 b6 30. Nb4 a5 31. Nd3. Although White looks better due to his pressure on e6, Black can actually hold out quite well in this position.

29. Nd3 e5?

This may look like strong counterplay, but it gives White an opportunity to unleash some tactics.

30. fxe5 fxe5
31. dxe5?

Throwing away his winning chances! White wins a pawn with the strong intermezzo 31. Qg3! e4 32. Qxd6 Nxd6 33. Nb4 winning.

31... Nxe5
32. Nxe5 Rxe5
33. Rxe5 Rxe5
34. Rf1 Qe7

Order from Chaos! Now the position is equal.

35. Rd1 Qf7

Making use of the exchange to centralize my king early.

36. Qxf7+ Kxf7
37. Kf2 Ke6
38. g4 Re4
39. Kf3 Ke5
40. h4 (D)

Position after 40. h4

40... b5

Here the endgame looks slightly better for me: My king is more centralized, my rook is more active and my isolated d4 pawn can be pushed anytime. But rather than exchanging it off straightaway it is better to deprive my opponent of space first. 40... d4 41. cxd4+ Rxd4 42. Re1+ Kd5 43. Re7 would give me unpleasant problems that I prefer to avoid.

41. b3 a5
42. a3 g6
43. h5 gxh5
44. gxh5 h6
45. Rh1

But now what? Pushing the queenside pawns gives White the chance to create passed pawns on that wing.

45... Kf5

Once again I did not like 45... d4 46. cxd4+ (46. c4? bxc4 47. bxc4 Re3+ is winning for Black.) 46... Rxd4 47. Re1+, while 45... b4 46. cxb4 axb4 47. a4 gives White a passer on the a-file.

46. Rd1 Ke5
47. Rh1

For a moment I was almost tempted to accept the draw!

47... Kf5
48. Rh2 Re5
49. Rh4 Re4
50. Rxe4?

Giving me an outside passed pawn. Better was 50. Rh1 and now I would really be forced to choose between pushing d4 or just accepting a draw.

50... dxe4+
51. Ke3 Ke5
52. b4 a4 (D)

Position after 52... a4

White's innocent looking mistake has given me a huge advantage.

53. Ke2

53. c4 bxc4 gives White his own passer, but after 54. b5 c3 55. b6 Kd6 Black catches the pawn while White cannot handle both of Black's passers.

53... Kd5
54. Ke3 Kc4

The passed pawn draws away the enemy king while my king gobbles up the queenside pawns. Now it's all over.

55. Kxe4 Kxc3
56. Kd5 Kb3
57. Kc5 Kxa3
58. Kxb5 Kb3
59. Kc5 a3
60. b5 a2
61. b6 a1=Q
62. b7 Qa7+
63. Kc6 Qb8 (D)
0-1

Position after 63... Qb8

A long and complicated battle. Here are some pointers we can take away from this game:

  1. The minority attack is a useful technique that allows you to create a weakness in your opponent's structure; in this game I missed the chance to do so
  2. Weak squares in the opponent's camp are strong outposts for the knight
  3. Going for a pawn push is useful for removing your pawn weaknesses... but look out for potential tactics first
  4. Centralize your king early in the endgame
  5. If your opponent has an endgame advantage (e.g. passed pawn), try not to trade your pieces!

Sources:
http://www.theultraviolet.com/wordpress/2012/10/time-to-tidy-up/

Saturday, July 4, 2015

Norway's Rook Endgame Showdown

Norway Chess never fails to give us wonders. Just last week we witnessed a fine attacking game between Anand and MVL. In the same round, another fighting game materialized between Carlsen and Nakamura. After a long and tiring struggle, the following position was reached:

Carlsen, Magnus vs Nakamura, Hikaru
Norway Chess 2015 Round 6
Position after 38. Rxc2

This may look like a complicated scenario, and Black cannot save that pawn on c2. However, Nakamura found a way to simplify the game by trading off all the Queenside pawns, leaving behind a 4 vs 3 position that is a theoretical draw. So let us look at how Black defends accurately in this rook endgame, and take it as a refresher of what we have gone through earlier.

38. Rxc2 Rc5

"The maneuver Kg1-f2-e2-d3 with pawn gain is inevitable, but Black has enough time to swap off the remaining pair of pawns on the queenside, thus reaching a theoretically draw endgame four versus three on the same flank." - Bojkov

39. Kf2 b5!
40. axb5 Rxb5
41. Rxc3 g6!
42. f4 h5!

"The best set up of the pawns on the kingside. Black is ready to trade them at the moment White starts advancing there." - Bojkov

43. Rc8+

If 43. Kf3 then 43... Rb4 followed by a5-a4.

43... Kg7
44. Ra8 Rxb3
45. Rxa5 (D)

Position after 45. Rxa5

Now we have a 4 vs 3 endgame. Black's pawn structure prevents White from grabbing too much space in the centre. This allows Black to draw by keeping his rook active, and seeking out soothing pawn exchanges.

45... Rb2+
46. Kf3 Rb3
47. Ra7 Rc3
48. Re7 Rb3
49. Kg3 Rb2

Notice how Black's rook ties down White's king to defending his pawns.

50. Kf3 Rb3
51. g4 hxg4+
52. hxg4

Trading one pair of pawns. Now it's a 3 vs 2.

52... Rb1
53. Rd7 Rf1+
54. Ke4 Rg1
55. g5 (D)

Position after 55. g5

White wants to use his pawns to grab enough space to "squeeze" Black.

55... Ra1
56. Ke5 Ra3

Black simply continues using his rook to interfere with White's plans.

57. e4 Ra5+
58. Kd6 Ra6+
59. Ke5 Ra5+
60. Rd5 Ra4

Wisely avoiding the rook trade. 60... Rxd5+?? 61. exd5 is winning for White.

61. Rc5

Or 61. f5 gxf5 62. exf5 reaching an easily drawn 2 vs 1 position.

61... Ra1
62. Rc2 Rf1
63. Rc7 Re1
64. Ra7 Rg1
65. Ra4 Rf1
66. Ra6 Re1
67. Kd4 Rd1+
68. Ke3 Re1+
69. Kf3 Rf1+
70. Kg3 Re1
71. e5 Re3+
72. Kf2 Rb3 (D)

Position after 72... Rb3

Cutting off White's king from the pawns. Once again, the key to drawing lies in active rook play!

73. Rd6 Ra3
74. Rd8 Rc3
75. Ke2 Ra3
76. Rd3 Ra1
77. Ke3 Re1+
78. Kd4 Rf1
79. Ke4 Ra1
80. Rd7 Ra4+
81. Rd4 Ra5
82. Rc4 Kf8
83. Rc8+ Kg7
84. Rc7 Kf8
85. Kd4 Ra4+
86. Rc4 Ra5
87. Rc8+ Kg7
88. e6 (D)

Position after 88. e6

The last slim chance.

88... fxe6
89. Rc5 Ra7

89... Rxc5?? 90. Kxc5 would really win for White, but no one is buying this.

90. Ke5 Rf7
91. Rc4 Rf5+
92. Kxe6

With an easily drawn 2 vs 1 position. Carlsen finally decides that he has enough.

92... Kg8
93. Rc8+ Kg7
94. Rc7+ Kg8
95. Rc8+ Kg7 (D)
1/2-1/2

Position after 95... Kg7

This game shows how important it is to have a good understanding of rook endgames. Without the necessary foundations, Nakamura would not have been able to defend correctly and secured the half-point.

Sources:
ttp://www.chess.com/news/topalov-also-beats-grischuk-now-15-points-ahead-of-the-pack-5174