Know How in the Pawn Endgames (1)

Concept:
The knowledge of exact positions is the cornerstone in the understanding of the pawn endgames.
The pawn endgames have their own specifics. Contrary to the other endgames where we can use approximate evaluations like slightly better/worse or much better/worse without definite conclusion, in the pawn endgames we use only three evaluations- win/draw/loss.
The lack of material enables us to calculate the lines till the end but this is easier said than done. At the end of the game players are usually tired and tend to make more mistakes. The time troubles also do not contribute to the proper calculations.
To sum the things up- pawn endgames can be easily compared to mathematical task where you have only one true answer. In order to find this answer the knowledge of a concrete theorem is needed in mathematics, while in chess that would be the knowledge of a concrete exact position.
Let's have a look of a case where one of the opponents is lacking essential exact knowledge. The following game was played at the first Metropolitan open tournament in Los Angeles three years ago. The player who has the white pieces is a strong national master Mikhail Langer. His opponent is a young and promising IM from Canada, Raja Panjwani. It was actually Raja who showed me the game immediately after it was over. It is a strange coincidence as you will see in a moment. In the diagrammed position White chose the natural looking:

[Event "Los Angeles Metropolitan op 1st"]
[Site "Los Angeles"]
[Date "2011.08.17"]
[Round "1"]
[White "Langer, Mikhail"]
[Black "Panjwani, Raja"]
[Result "0-1"]
[ECO "B02"]
[WhiteElo "2180"]
[BlackElo "2420"]
[Annotator "Mьller,Karsten"]
[SetUp "1"]
[FEN "8/3p1p2/8/4P3/3K4/6k1/8/8 w - - 0 80"]
[PlyCount "8"]
[EventDate "2011.08.17"]
[EventRounds "9"]
[EventCountry "USA"]
[Source "Chess Today"]
[SourceDate "2009.03.11"]

{Diagram [#]} 80. Ke3 $2 {The most natural reply appears to be the first and
the last mistake in the endgame. The normal opposition is wrong here as White
cannot keep it up on all the squares.} ({White needed to choose the distant
opposition!} 80. Kc3 $1 {[%csl Gc3,Gg3] this was the only way to draw. For
example-} Kf4 81. Kd4 Kf3 82. Kd3 Kg2 83. Kc2 {[%cal Rc2d2,Rd2e2,Rg2f2,Rf2e2]}
Kg1 84. Kc1 Kf2 85. Kd2 Kf3 86. Kd3 Kf4 87. Kd4 Kf5 88. Kd5 {when Black can
make no progress and the game should end in a draw-} f6 89. exf6 Kxf6 90. Kd6)
({On the other hand, the immediate aggression is wrong on the account of-} 80.
Kd5 $2 Kf3 $19 {[%csl Gd3,Gd5,Gf3,Gf5][%cal Rd5e4,Rf3e4] Black wins the
diagonal opposition and outflanks the opponent's king-} 81. Kd4 Kf4 {[%csl Re5]
} 82. Kd5 Ke3 {[%cal Re3d4,Re3e4]} 83. Kd6 Ke4 84. Kxd7 Kxe5 $19) ({Also wrong
is:} 80. Ke4 $2 Kg4 {[%csl Re4,Ye5][%cal Gg4g5,Rg4f4,Rg4f3,Rg4f5,Yf5e5]} 81.
Ke3 Kf5 82. Kd4 Kf4 {which transposes to the previous note-} 83. Kd5 Ke3 84.
Kd6 Ke4 85. Kxd7 Kxe5 $19 {[%cal Gf7f5]}) {The many lines in which White could
have gone wrong should convince you that things are not as simple as they look.
The game saw-} 80... Kg4 81. Ke4 Kg5 {[%csl Re5][%cal Re4e5] Diagram [#] Now
White can not maintain the vital normal opposition as the e5 square is not
available for his king.} 82. Kd4 (82. Ke3 Kf5 83. Kd4 Kf4 84. Kd5 Ke3 $19)
82... Kf4 {[%csl Gd4,Gf4] Opposition} 83. Kd5 Ke3 {Outflanking. White resigned
due to the line:} (83... Ke3 84. Kc5 Ke4 85. Kd6 Kd4 86. Kxd7 Kxe5 87. Ke7 f5
$19) 0-1

Panjwani did his homework which cannot be said for his opponent. He knew long before the game the following classical example:

[Event "?"]
[Site "?"]
[Date "1890.??.??"]
[Round "?"]
[White "Neustadtl"]
[Black "Combined oppositions"]
[Result "1/2-1/2"]
[Annotator "Bojkov, Dejan"]
[SetUp "1"]
[FEN "8/8/8/4p1p1/8/5P2/6K1/3k4 w - - 0 0"]
[PlyCount "11"]
[Source "Chess Today"]
[SourceDate "2009.03.11"]

{Diagram [#]} 1. Kh1 $8 {[%csl Rf1][%cal Rh1g1,Rd1e1,Re1f1,Rg1f1] Distant
opposition saves the day.} ({Once again bad is the normal one-} 1. Kf1 $2 Kd2
2. Kf2 Kd3 {[%csl Rf3][%cal Rf2f3]} 3. Kg3 Ke3 {[%csl Re3,Rg3]} 4. Kg2 Ke2 5.
Kg3 Kf1 $19 {[%csl Rf1,Rg3] Outflanking!}) 1... Kd2 ({Black has one more
resource in his disposal-} 1... g4 {but after-} 2. Kg2 {[%cal Rg2f3,Rf3e4,
Re4e5] the draw is inevitable-} gxf3+ ({Or:} 2... Ke2 3. fxg4 e4 4. g5 e3 5. g6
Kd2 6. g7 e2 7. g8=Q e1=Q $11) 3. Kxf3 Kd2 4. Ke4) 2. Kh2 Kd3 3. Kh3 Ke3 4. Kg3
Ke2 5. Kg2 Ke1 6. Kg1 1/2-1/2

Panjwani did his homework which cannot be said for his opponent. He knew long before the game the following classical example:
The lack of know-how prevented Langer of saving the half point after a tough and accurate resistance. Panjwani on the other hand knew the position and if the colours were reversed he would have easily saved the game. The knowledge helped him in the game as well as he knew exactly how to win after his opponent committed a mistake.
(To be continued.)