Thursday, January 30, 2014

Rook vs Rook + Connected Passed Pawns

Apologies for the long stretch of silence these few weeks, I was weighed down under external commitments so could not find the time to post here. But now since all the rush is over for me, let us continue with what I have promised to show everyone: How to win with a rook + two connected passed pawns.

White to play and win

Now once again, the win is not very difficult once you've got the general idea, but precise play is needed if you're to avoid the many drawing traps which Black can throw at you! Also, do note that knight and rook connected pawns are often the hardest case (which is what we are going to look at now); once you've mastered that, then you will not have too much difficulty with connected central pawns.

The trick to winning this easily is to make sure you keep your pawns advancing together so that they can protect each other; don't let one pawn charge forward on its own only to get mowed down by machine-gun fire! The king must also stay close to the pawns, both to escort them and to use them as protective cover against enemy rook checks. Who says teamwork isn't necessary when playing chess?



1. Kh3

Stepping up to support the pawns

1... Kf6
2. g3

Of course 2. g4 is possible but it is always good to keep the g4 square open for the king, in case he needs some shelter from enemy rook checks.

2... Rf1

Similar to the Philidor Position (I hope that rings a bell!), Black threatens to lay down a barrage of checks from the back rank, and this is one of the many drawing threats which White must prevent. Another variation is 2... Ra4 3. g4 Ra1 4. Rf5+ Kg7 5. Kh4 Rh1+ 6. Kg5 leading to similar gameplay which we will encounter later on in the main line.

3. Kg4

This move serves two purposes: White uses the g3 pawn as protective cover against Black's checking threats, and also prepares to push back the Black king.

3... Rf2

Also possible would be 3... Ra1 4. Rd6+ Kg7 (4... Ke7 5. Rb6 Ra4+ 6. Kg5 Ra5+ 7. Kg6 and the White king can safely escort the h-pawn up to promotion) 5. Kg5 Ra5+ 6. Kh4 Ra4+ 7. g4 going back to our main line analysis

4. Rd6+ Ke7
5. Ra6 Rc2
6. Kh4 (D)


A shelter for the White king

Once again notice that White can use his g-pawn to shield his king from checks: 6... Rc4+ 7. g4 or 6... Rh3+ Kg4

6... Kf7
7. g4 Kg7
8. h6+

After 8. g5? White will have no cover for his king, and for Black that means... UNLEASH THE BARRAGE!!!! (8... Rc4+)

Another possibility for White will be 8. Ra7+ Kh8 (8... Kh6?? leads to 9. g5#, while after 8... Kf6? 9. g5+ Kf5 10. Rf7+ Ke6 11. Rf6+ Ke7 12. h6 Rh2+ 13. Kg4 Rg2+ 14. Kh5 Rh2+ 15. Kg6 White has sought shelter from the enemy rook, and Black's king is powerless to stop either pawn from promoting) which will return to our main line.

8... Kh7
9. Kh5 Rc5+

By now, the practice of using the pawn to shield your king from enemy checks should be familiar to y'all.

10. g5 Rb5

Keeping the pawn pinned; 10... Rc7? loses faster with 11. g6+ Kg8 12. Ra8+

11. Ra7+ Kh8

The other variation is 11... Kg8, where playing 12. h7+?? will be a mistake because of 12... Kh8 13. Kh6

Black to move, draw!

13... Rb6+ 14. g6 Rxg6+! 15. Kxg6 with a stalemate. This stalemate threat must be avoided at all costs!

The correct response to 11... Kg8 should be 12. Rg7+  12... Kh8 13. Re7 (and NOT 13. Kg6?? Rxg5! 14. Kxg5 with a draw) which returns to our main line.

Let us now return to our main line:

A critical moment

12. Re7!

Looks weird? But if you have been following me through the past few articles this should be familiar: It is similar to the "building a bridge" maneuver in the Lucena Position!

To elaborate further, the reasons behind this move are as follows:

  1. White wants to bring his king to f7, where the rook on e7 shields him from any 7th rank checks.
  2. If White's king is forced to f6, then 6th rank checks can be blocked with Re6 (building the bridge!).
  3. Once White can get his pawn to g6, the threat of back-rank mate will force Black's rook to fall back onto the back rank. Once that happens, White's king can march to f7/d7 and force a trade of rooks. The resulting king + connected passed pawns vs king should be an easy win thereafter.
Any other move does not fulfill these 3 purposes; for example after 12. Rd7 Rb8 13. g6 (13. Kg6 Rb6+ 14. Kf5 Rb5+ 15. Kf6 Rb6+ and White cannot hope to reach the 7th rank without hanging his g pawn) 13... Rb5+ 14. Kg4 Rb4+ 15. Kg5 Rb5+ 16. Kf6 Rb6+ 17. Kf7 Rb8 White will still have to play 18. Re7 anyway (and NOT 18. g7? Kh7 with a hanging h-pawn, or 18. h7?? Rf8+ 19. Ke6 Rf6+ with an inevitable draw) in order to save the game.

12... Rb8

The other variation will be 12... Kg8 13. Kg6 Rb6+ 14. Kf5 Rb5+ 15. Kf6 Rb6+ 16. Re6 (building the bridge!) 16... Rb8 17. g6 Ra8 18. h7+ Kh8 19. Kg5 transposing back to our main line.

13. g6

And once again not 13. h7?? where after 13... Rb7, 14. Rxb7 leads to stalemate while moving the rook away allows 14... Kxh7 with an upcoming Philidor Position and a subsequent draw. By now, we should all be aware about the dangers of pushing h7 too hastily, due to the many stalemate tricks that the Black can throw at us. The lesson learnt from here is this: Only push the pawn to h7 once you're absolutely sure the other side cannot use any sacrificial stalemate traps!

13... Rb5+
14. Kg4 Rb4+
15. Kf5 Rb8

If Black insists upon more checks with 15... Rb5+ then White simply marches his king to the sheltered 7th rank: 16. Kf6 Rb6+ 17. Kf7

16. Ke6 (D)

Patience is a virtue!

The threat of back rank mate has forced Black's rook to retreat to the back rank. Now, White's plan will be to force a trade of rooks and simplify the position into a winning pawn endgame. In this case, the threat is Kd7 followed by Re8+.

16... Ra8
17. Rd7

Black's last move unveiled the possibility of 17... Ra7+ which would follow should White play 17. Kd7. Thus White's rook gives extra space for the threat of Ke7 followed by Rd8+ forcing the exchange of rooks.

Now, the tempting 17. Kf7 gives Black the stalemate trick of  17... Rf8+, which will manifest after the bullheaded 18. Kxf8??. Fortunately, after 17... Rf8+ White can still save his point with 18. Ke6. 

17... Re8+
18. Kf7 Rg8

This time Black will not want to play 18... Rf8+ because of 19. Ke7 followed by 20. Rd8 (and another forced rook trade!)

19. g7+ Kh7
20. Re7 Ra8

Of course 20... Kxh6 falls prey to 21. Kxg8

21. Re8 Ra7+
22. Kf8 (D)
1-0

Time for Black to resign

There is no way to stop the promotion of the g-pawn, so the game is as good as won for White.

...

Looks too long and drawn-out? Let's sum up the general ideas behind winning this endgame:

  •  As the stronger side, make sure that both your pawns advance together; don't allow one pawn to perform a one-man show and botch up the entire operation.
  • Use the king to support the pawns, and use the pawns to shelter the king from enemy rook checks. Teamwork is necessary!
  • Use your rook and king to slowly push back the enemy king (by cutting off files with the rook) so that the pawns can advance safely.

When the pawns have advanced to the 6th rank or so, and the enemy king is stuck in a corner, keep in mind the following tips:

  • Using your rook to "build a bridge" on both the 7th and 6th ranks is essential to shelter your king from those pesky rook checks
  • When your king has safely made it to the 7th rank, the threat of back-rank mate will force the enemy rook to retreat to the back rank. When that happens, the most straightforward plan will be to force a rook exchange and simplify the endgame to an easily winnable position
  • Watch out for the sacrificial stalemate tricks! In this case, only push your pawns to the 7th rank once you're absolutely sure you have avoided these traps!

And thus the ways for you to mess up this endgame will be if: (1) You blunder your pawns/rook (2) You destroy your king's shelter by letting your pawns advance too far, thus exposing your king to an endless barrage of checks, and (3) If you have advanced far down the board and hastily push your pawns to the 7th rank without taking into consideration any possible stalemate tricks that the enemy can throw at you.

To fully familiarize yourself with this position, it is good to read through the summary and go through the variations again; and keep in mind that like all other endgames, patience is always a virtue!

And if you crave more challenge, you can try to apply this new-found knowledge to the position below. But since connected-knight+rook pawns are often more difficult than connected central pawns, you shouldn't find it too much of a problem!

Connected central pawns: White to play and win

Sources:
"Silman's Complete Endgame Course" by Jeremy Silman

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