Friday, March 6, 2015

Rook endgame practice 4

I guess I've given y'all enough time to attempt the challenge, so let's go through them:

Position 1: Black to move and save himself

This one is dead easy, so I expect most of you should have no problem with it. Unless you have been wearing an army helmet for the past week, in which I understand since your IQ would have dropped by 50%.

Despite having a passive rook position, Black can hold the draw here because White can't use the "swing the rook to the other side" trick (well you still remember what that means, do you?). So all Black needs to do is to play 1... Rc8! protecting his king from any checks, and White can do nothing in the world to touch him.

...

Position 2: White to move, can he still draw?

Note: This position (as well as Position 3) was edited slightly during the challenge (everything shifted 1 square to the left), so apologies for the mistake.

This should also be manageable, assuming you still remember the concepts behind the Inverse Philidor. After 1. Kg8! (moving the king to the short side of the board) White ties down the enemy pawn with his rook on f8, and can threaten to unleash checks from the long side with Rb8-Rb7 if needed. The full drawing procedure is given in the Inverse Philidor article.

With that in mind, we move on to our third position:

Position 3: White to move, can he still draw?

Surprising, but the change in 1 square suddenly turns the game from draw to defeat for White! Two factors contribute to this:

  1. White's rook is no longer eyeing the e4 pawn, giving Black's king the liberty to step forward if needed.
  2. The position of Black's rook ensures that White's rook has insufficient space on the long side of the board to unleash side-rank checks safely.


1. Kf1!

White correctly brings his king to the short side of the board, but unfortunately this is not enough to draw.

1... Ra1+
2. Kg2 Ke2!

Black's king is free to gain more space, since the e4 pawn is not attacked. Note the difference between this and the previous position!

3. Rb8

3. Rf2+ Kd3 4. Rb2 e3 is similar to the main line, while after 3. Re8 e3 4. Kg3 Kd2 5. Rd8+ Ke1 Black has an upcoming Lucena Position.

3... e3
4. Rb2+

White's rook has insufficient checking distance (only two squares apart). Notice that if everything were shifted one square to the right, White would draw since after Ra8-Ra2+ he would have sufficient checking distance!

4... Kd3 
5. Rb3+ Kd2
6. Rb2+ Kc3
0-1

And White cannot stop the pawn from advancing, with an upcoming Lucena Position.

...

Position 4: Black to move. Assess the position.

This looks like a complex position, but by recalling our basics we can identify with some positions we looked at in the past. A passive rook in front of its pawn, with the enemy rook behind... perhaps this article can stir up memories? And indeed it is useful for us in solving this problem.

While White is two pawns up, Black can swindle a draw if he is able to get a Vancura Position, or can trade the queenside pawns in such a way that White will be left with a g or h pawn on the queenside (which will be a draw so long as Black's king stays on g7/h7). However, an analysis of the position shows that he will not be able to achieve either of these objectives:

1... hxg5

The best try; 1... fxg5 loses immediately to 2. f5! after which the f-pawn will pull Black's king off the critical g7/h7 squares.

Trying to get a Vancura Position here won't work: 1... Rc2 2. gxf6 Kg6 3. a7 Kxf6 4. Rf8+ and White wins.

2. hxg5

Of course 2. fxg5? fxg5 3. hxg5 is a draw since Black's king cannot be chased off g7.

2... f5

After 2... fxg5 White keeps his pawn on the f-file: 3. f5! (3. fxg5? is a draw since 3... Ra5 4. Kd2 Rxg5 5. Kc3 Rg6! allows Black to set up a Vancura Position.) 3... Kg7 4. a7 g4 5. f6+ (Pulling the king off the g7 square) 5... Kxf6 6. Rf8+ +-

3. a7 Kg7
4. Kd1

White's king wants to win the f5 pawn, so he marches slowly towards the Black rook first to break free from its restraint.

4... Kh7
5. Kc1 Kg7
6. Kb1 Ra3
7. Kb2 Ra5
8. Kb3 Ra1
9. Kc4 Rc1+
10. Kd4 Rd1+


10... Ra1 11. Ke5 Ra5+ 12. Ke6 Kh7 13. Kf6 +-

11. Ke5
1-0

The f5 pawn falls, and together with it Black's game.

...

So hopefully you managed to revise most of your basics through these challenges. Let's explore even further as time goes by!

Links:
Practice 1: http://nushsblackknights.blogspot.com/2014/12/rook-endgame-practice-1.html
Practice 2: http://nushsblackknights.blogspot.com/2014/12/rook-endgame-practice-2.html
Practice 3: http://nushsblackknights.blogspot.com/2015/01/rook-endgame-practice-3.html

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

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