Basic Endings: Rook vs Knight

vs

This is one of the 100 endgame you must know, says GM Jesus de la Villa. It was also the subject of the first recorded chess endgame study by Al-Aldi in 842 AD.

I. Evaluation & Principles

• 71% draws.
• Usually won if the knight ventures away from his king's protection.
  
• Usually won if the knight's in a corrner (red zone).
  
• Winning chances with a knight on the rim (yellow zone¹).

[08-Oct-2008 update: Added b4, b5, d2, d7, e2, e7, g4, and g5 to the yellow zone.]

II. Technique

While the above will help you determine whether to enter a rook vs knight endgame, you need to know more to actually play it well. Read on to learn more. :)

Trapping a Separated Knight

[FEN "7R/k7/8/1K6/8/1n6/8/8 w - - 0 3"]
3. Rd8 Nc1 4. Rd2 Nb3 5. Rd1

1.Rd8! confines the knight, the first step towards winning it. Finishing off the knight is straight-forward: 1...Nc1 2.Rd2 Nb3 3.Rd1 or 1...Na1 2.Rd2 Nb3 3.Rd1.²

Surviving on the Rim

[FEN "3KN3/7r/8/3k4/8/8/8/8 b - - 0 5"]
5... Ke6 6. Nc7+ Kd6 7. Ne8+ Kc6 8. Kc8 Rh8 9. Kd8 Rh7 10. Kc8 Ra7 11. Kd8

White's knight prevents the Black king from occupying d6, e6, or f6. If the rook attacks on the eighth rank, White can survive by escaping via the e7 flight square.

More Complicated Cases

These examples may mislead you into believing this ending is simple. Nothing could be further from the truth. Even super-GMs can goof, and amateur games are often comedies of errors.

rn-pos-3.pgn

As you play over the above game, can you spot all the mistakes? Every ?? indicates one side blundered so badly the result changed from won to drawn or vice-versa.

III. Mastery

"This time, let go your conscious self and act on instinct." -- Obi-Wan Kenobi

When your clock is down to 5 seconds/move, it's not enough to know the winning technique. You must be able to play on instinct, as smoothly as you swim or ride a bike. Once you reach this level of mastery, you never forget. You've never forgotten how to swim, have you? ³

GM Yasser Seirawan learned this endgame by playing a simple game. He put only a white rook, white king, and black knight on the board. He then moved the White pieces and Black pieces in turn (Black is allowed to pass!) and saw how quickly he could hunt down the knight.

Play this for a few minutes a day for the next month. :)

Footnotes

¹ - Specifically, if the knight's in the red zone it can be immediately trapped by either the king or rook. If the knight's in the yellow zone it can be trapped by the king and rook together. I find this a useful way to gauge the relative danger of squares.

² - This position arises in a line from the Al-Aldi 842 AD endgame study.

³ - For the scientifically inclined, It's stored in your procedural memory. Experimental evidence proves this knowledge even survives many forms of amnesia.

Queen & Pawn vs Queen

Q+P vs Q is more common than Q vs P, but it receives less coverage. That's probably because it's complex, and in fact humans knew little about this ending until the advent of tablebases revolutionized its study.

Rook and Knight pawns usually draw if:

• the defending king reaches the promotion corner.
• the defending king reaches the corner opposite the promotion corner.

Bishop and Central pawns usually win unless:

• the defending king gets in front of or very near the pawn

The weaker side should get their king to a drawing zone, perpetually check the attacker, avoid queen exchanges, and avoid pawn advances.

The stronger side should prevent the defending king from reaching a drawing zone, move their king to the same rank or file as the attacking king to threaten a queen exchange, centralize their queen, and advance their pawn.


In the above diagram, both kings are on the same rank, so Black must be careful to avoid queen exchanges. 1...Kc3?? 2.Qe5+! Qxe5+ 3.Kxe5 +-

And that's what you need to know in a nutshell.   :)

Further Resources:

• Fundamental Chess Endings, pgs 316-321
• Queen and Rook's Pawn vs Queen I
• Queen and Rook's Pawn vs Queen II

How to Play Endgames Brilliantly

View Article

What have I been up to? I read "Improve Your Opening Play" and "Dealing with d4 Deviations" over vacation. Opening study is one of the least rewarding types or study, but now I have a basic idea of what to do when faced with the Trompowsky, Torre, London, or Colle.

This week I've been reviewing pawn endings. I analyzed 632 K+P vs K, 505 K+P vs K+P, and 90 K+P vs K+2P endings as a refresher. Very entertaining. :)

dktransformation's ending

 


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This is an exciting ending played by my friend dktransformation. I think it's practical and it contains interesting positions, mistakes, and nuggets of wisdom that we can learn from.

Frontal Defense IV

 


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This is my final article on the Frontal Defense. We look at positions from real games. These are complicated positions, so don't feel bad if you miss a move.

Frontal Defense III

 


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We're going to look at Frontal Defense on the knight file today, and then examine some interesting games between strong players.

Frontal Defense II

 


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Now that you know how wage a Frontal Defense, we're going to learn how to quickly evaluate whether a position can be drawn via this method.

Frontal Defense

 


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The Frontal Defense was invented by Tarrasch. It's a method that a defender can use to draw a R+P vs R ending when his king is cut-off from the pawn.This technique is only effective if the pawn hasn't crossed the middle of the board.

Rook f-, & h-pawns vs Rook

This is one of the few ways to draw when you're two pawns down. I found an interesting resource on the Internet for mastering this ending:

Rook endings with rook and bishop pawns

In this free lesson Peter Joseph covers 32 R+P vs R endings and 16 R+2P vs R endings. There are some real gems in his writings:

• Why against a central pawn the defender's rook needs 3 files of checking distance, but against a bishop pawn the defender's rook only needs 2 files of checking distance.


• A simple formula you can use in frontal attack positions with bishop pawns to determine if the endgame is a draw without having to calculate.


• How the attacker can try to win... by sacrificing the rook pawn to arrive at a won R+P vs R ending, or by driving the enemy king to the back rank.

Enjoy at your leisure, and have a great weekend.   :)

Rook vs Bishop

 


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For players under 2100, Rook vs Bishop is won 40% of the time. The drawing technique is counter-intuitive, so if your opponent doesn't know it, you have chances to win.

Queen vs Knight

 


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Queen vs Knight is a simple win, but when you reach it you may be tired and in time trouble. You also must watch out for forks! See how a strong master goofed it up, then learn a simple trick that makes disappointments unlikely.

Queen vs Bishop

 


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This article may be too simple for some readers, but in my Bishop and Pawn vs Bishop and Centurini Position articles I frequently said Q vs B is an easy win. Then I witnessed a tragicomedy, and thought maybe I should offer a couple tips! :)

Centurini Positions

 


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A Centurini Position is one where one of the two diagonals in front of the pawn is less
than four squares in length. These are almost always won.

Bishop and Pawn vs Bishop

 


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View Tragicomedy

If Knight endgames are about flashy tactics, Bishop endgames are about subtle finesse. Enjoy and learn from my selection of five practical positions.

Zugzwang & Steinitz's Rule

Simba writes, Thanks for posting [Karpov-Hort, Budapest 1973] and your commentary which is very informative. Got one question: What does 'spare tempi in zugzwang situations' mean when white moved g5 in move 35?


Zugzwang means it's a disadvantage to have the move.



In the above position, Black to move loses and White to move draws. Such positions are called zugzwang positions and they're very common in the endgame. It's astonishing the first time you see such a position, because in the opening it's an advantage to have the move!



Steinitz's Rule: Keep some pawns on their starting squares, because there they often provide reserve tempi in zugzwang positions.


With a-pawns onboard, the situation's more complicated.

In the first diagram, Black to move draws with 1...a6! a4 a5 and now it's White to move in our original zugzwang position. But he loses with 1...a5?? 2.a4 as now it's Black to move.

In the second diagram, Black to move draws with 1...a5! and now it's White to move in our original zugzwang position. But he loses with 1...a6?? 2.a5 as now it's Black to move.

In the third diagram, Black loses either way. 1...a5 2.a4! and it's Black to move in the original zugzwang position. 1...a6 2.a3! a5 3.a4 and again it's Black to move.



Not every endgame reaches a zugzwang position, but many do, and now you know why it's a good idea to leave some pawns on their starting squares.   :)

Karpov-Hort, Budapest 1973

 


View Annotated Game

A fascinating and instructive endgame. I hope you enjoy it as much as I have, and that it teaches you something. Feel free to ask if you have any questions! :)

B+N+P vs B+2P

 


View Annotated Game

This ending is a great example of how a bishop, knight, and king can work together. It's shamelessly stolen from "Analysis on The ENDGAME" by ugralitan, but his article didn't cover these lines. I hope you will find this annotated game enjoyable and educational. :)

Week in Review, Sep 28

Rook and Pawn vs Rook endings are the most common ending in practice, and they're more complex than most players realize.

Rook Endings - [External] An introduction to Lucena and Philidor.

Lucena, not so simple? - An average player believes he wins easily if he reaches Lucena. We learn that's often not the case!

Not Quite Lucena - Describes the proper defense and common mistakes.

Not Quite Lucena II - Describes how the attacker can break down an improper defense--a misplaced king.

Not Quite Lucena III - Describes how the attacker can break down an improper defense--a misplaced rook.

Kopaev, An Instructive Endgame - An incredibly instructive endgame that tests your knowledge of zugzwang and the previous lessons.

Kopaev's Instructive Endgame

Read my new article, Kopaev's Instructive Endgame. It's a practical, instructive, and challenging Rook & Pawn vs Rook position.



The animated diagrams make it easier to explain on my other blog.   :)

Not Quite Lucena III

Not Quite Lucena positions feature the attacker's pawn on the sixth rank with his king in front of the pawn and are quite common in practice.

This is the final article in my series on Lucena. You may want to read through the earlier ones here, here, and here if you haven't already.



Today, we'll learn how to crush another inaccurate defense--a misplaced rook. Defenders goof in over 80% of such positions. So my advice to you is to be patient until an opportunity presents itself, and then be swift in exploiting it!

Mistake #3: The defending rook is less than 3 files away

Black to move. White is threatening Rg1+, initiating a Lucena maneuver, so Black must either initiate a passive defense with Rg1 or an active defense with Rb8+. By now, you know that an active defense is almost always the best plan.

1...Rb8+ 2.Kd7 Rb7+ 3.Kd6 Rb6+ 4.Kc7 and we reach this position:



An important point is that Black can't reposition his rook on the b-file. The only moves that stop White from queening this turn are:

4...Re6 5.Kd7 +-.

4...Kf7 5.Kxb6 +-.

White wins, because Black's rook was misplaced on the b-file.

Mistake #4: Thinking a misplaced piece is always fatal

Black to move. It's important to know that a misplaced rook or king is not always fatal, especially if the attacker's pawn is not too far advanced. In this position, Black can miraculously save himself with an active defense in spite of his misplaced rook.

1...Rb7+ 2.Kd6 Rb6+ 3.Kd7 Rb7+ 4.Kc6 and we reach this position:



As in the last position, two of Black's defenses fail:

4...Re7 5.Kd6 +-.

4...Kf6 5.Kxb7 +-.

But now, Rb2 or Rb3 or Rb4 draw! Moving along the b-file fell to e8=Q in the last position, but here e8=Q is impossible. What about e7?

4...Rb2 5.e7 Kf7!! 6.Re1 Ke8 and it's a Lucena no more.



I hope this series of articles has helped to deepen your understanding of one of the most important endgames in chess. I know I learned something.