Basic Endings: Rook vs Knight

Submitted by likesforests on Sun, 10/05/2008 at 3:25pm.

Rook vs Knight

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).

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

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

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.

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.

» posted in Endgames
« Previous | 1 2 | Next »

Comments:

by likesforests - 2 months ago
United States
Member Since: May 2007
Member Points: 3559

Thanks everyone! Note, I fixed a flaw in the color-coded diagram that begins this article by adding b4, b5, d2, d7, e2, e7, g4, and g5 to the yellow zone. A knight on these squares can be immediately trapped by a rook and king working together.

by Dmaster995 - 2 months ago
Yonkers, NY United States
Member Since: Jun 2008
Member Points: 147

Excellent!

by xbigboy - 2 months ago
Minnesota United States
Member Since: Oct 2007
Member Points: 2256

Great stuff!

by seanki - 3 months ago
Pittsfield,Massachusets United States
Member Since: Jul 2008
Member Points: 385

that is a very good article. Keep up the good work!Wink

by Theodred - 3 months ago
Birmingham England
Member Since: Jun 2008
Member Points: 174

Really Interesting! I'm looking forward for more ^^ [Hint Hint]

by RaZhaN-k - 3 months ago
suleymany Iraq
Member Since: Jul 2008
Member Points: 1492

thank you very much ..i understand now

by ouverture - 3 months ago
Rotterdam Netherlands
Member Since: Oct 2008
Member Points: 8

I smirked at the Star Wars reference. The content of this article was very informational, well brought and easily understandable. Thank you for sharing this.

by EnGliSHCheSsPlAy - 3 months ago
Italy Italy
Member Since: Dec 2007
Member Points: 558

wow..really good lesson!

by farbror - 3 months ago
Uppsala Sweden
Member Since: May 2007
Member Points: 1602

They need to start paying you for excellent posts!! Well Done again!

by normajeanyates - 3 months ago
london [often in calcutta india] England
Member Since: Jan 2008
Member Points: 2151

likesforests>normajeanyates, thanks for the additions!

nice of you to say that - but that's ooold material - needs updating... you did that for K+R  v K+N, but K+R v K+B remains to be updated, so: [read on ;]

likesforests>While working late in my office, I didn't want to bite off another section of my system. Your message and Ozzie's tempted me... I began spending time alone with the rook and the knight... and one thing led to another.  ;)

 

So, I hope a Bishop is born ;)

by normajeanyates - 3 months ago
london [often in calcutta india] England
Member Since: Jan 2008
Member Points: 2151

likesforests, I should add that I'll definitely practise this endgame.

But first I'll practise K+Q v K! Next, K+R v K! Reason:

Yesterday (at fics 3 0 blitz) I couldn't win with K+Q v K with almost 5 whole seconds remaining on my clock! In two games! :( [It is no excuse that I was *very* tired - in truth I never bothered to practise the 'shortcut' method for K+Q v K, likewise for the shorter 'boxing in' method for K+R v K :(]

by likesforests - 3 months ago
United States
Member Since: May 2007
Member Points: 3559

Sas3, glad it helped. May the force be with you in your game.

by likesforests - 3 months ago
United States
Member Since: May 2007
Member Points: 3559

normajeanyates, thanks for the additions!

While working late in my office, I didn't want to bite off another section of my system. Your message and Ozzie's tempted me... I began spending time alone with the rook and the knight... and one thing led to another.  ;)

by normajeanyates - 3 months ago
london [often in calcutta india] England
Member Since: Jan 2008
Member Points: 2151

BrianplaysTrashed >The exeption is if you venture too far from the king as is stated at the start

Are you saying that to Edward Lasker? He is not available for comment, owing to having died looong ago :) I am just the messenger...

by BrianplaysTrashed - 3 months ago
Santa Clara United States
Member Since: Oct 2008
Member Points: 18

The exeption is if you venture too far from the king as is stated at the start

by normajeanyates - 3 months ago
london [often in calcutta india] England
Member Since: Jan 2008
Member Points: 2151

I'll also soon post all the Reti studies on K+R v K+B wins that I have - diagramming too many would be clumsy to access if I do it, so I'll post pgns and diagram *one* of them.

Unless Ron (or someone else) does it before I do...

[I'd do it right now if I had them in digital format - as it is I have to type them out from my old pen-and-paper notes...]

PS: I hope that the commitment I made in the first paragraph gets stored in my procedural memory :-/

by normajeanyates - 3 months ago
london [often in calcutta india] England
Member Since: Jan 2008
Member Points: 2151

Ron [likesforests], i fear I may have diverted you from My System lesson eight - or retreived you back to your first chess-love --- endgames  -- depending on one's POV ;)

And I thought you were busy otherwise [ie non-chesswise] :)

--

jokes apart, this one is a very important article. I was planning to put up K+R v K+N wins and K+R v K+B wins some day [i said that in ozzie's thread] - but now that you have taken on that burden, you have and will of course do a much better job of it than I ever could. [for one - in the 'difficult cases' I'd be lost...]

-- i'll only contribute my 2d. worth by copying and pasting from Ed. Lasker's 'chess strategy' ch.5 for people to update, add to, and present properly... (no fear; copyright's expired on this book):

[from Edward (not Dr Emanuel!) Lasker's 'chess strategy' chapter 5]

The Rook can win against a minor piece in exceptional cases only.
In endings of ROOK AGAINST BISHOP the weaker King must take
refuge in a corner square of different colour from that of his
Bishop. For instance, Diagram 46:

        ---------------------------------------
     8 |    |    |    |    |    |    |    | #K |
       |---------------------------------------|
     7 |    |    |    |    |    |    |    |    |
       |---------------------------------------|
     6 |    |    |    |    |    |    |    | ^K |
       |---------------------------------------|
     5 |    |    |    |    |    |    |    | ^R |
       |---------------------------------------|
     4 |    |    |    |    |    |    |    |    |
       |---------------------------------------|
     3 |    |    |    | #B |    |    |    |    |
       |---------------------------------------|
     2 |    |    |    |    |    |    |    |    |
       |---------------------------------------|
     1 |    |    |    |    |    |    |    |    |
        ---------------------------------------
         A    B    C    D    E    F    G    H

                Diag. 46.

1. R-Q5, B-B5 (or R2); 2. R-Q8ch, B-Kt1, and Black is stalemate
unless the Rook leaves the eighth Rank.  Any outside square which
is not of the same colour as that of the Bishop is dangerous for
the King. Imagine the pieces in Diagram 46 shifted two squares
towards the centre of the board, as in Diagram 47, and White wins
with

          1. R-QKt5          B-R5
          2. R-Kt8ch         B-K1
          3. R-R8

The Bishop is lost, as it is Black's move.

In endings of ROOK AGAINST KNIGHT, the weaker side loses, where
the Knight is cut off from his King.

For instance, in Diagram 48, 1. R-Q5! In this "oblique
opposition" the Rook takes four of the Knight's squares:  1. ...
Kt-K8; 2. K-B5, Kt-B7; 3. K-K4, Kt-R6 (Kt-Kt5?; 4. R-Kt5ch! wins
the Knight). In this ending there is always a fatal check at some
point, and the position in the

        ---------------------------------------
     8 |    |    |    |    |    | #K |    |    |
       |---------------------------------------|
     7 |    |    |    |    |    |    |    |    |
       |---------------------------------------|
     6 |    |    |    |    |    | ^K |    |    |
       |---------------------------------------|
     5 |    |    |    |    |    | ^R |    |    |
       |---------------------------------------|
     4 |    |    |    |    |    |    |    |    |
       |---------------------------------------|
     3 |    | #B |    |    |    |    |    |    |
       |---------------------------------------|
     2 |    |    |    |    |    |    |    |    |
       |---------------------------------------|
     1 |    |    |    |    |    |    |    |    |
        ---------------------------------------
         A    B    C    D    E    F    G    H

                Diag. 47

diagram is not in any way a chance win. 4. K-Q3, K-B2; 5. R-QR5,
Kt-Kt8; 6. R-R1, and wins.

        ---------------------------------------
     8 |    | #K |    |    |    |    |    |    |
       |---------------------------------------|
     7 |    |    |    |    |    |    |    |    |
       |---------------------------------------|
     6 |    |    |    |    |    |    | ^K |    |
       |---------------------------------------|
     5 |    |    | ^R |    |    |    |    |    |
       |---------------------------------------|
     4 |    |    |    |    |    |    |    |    |
       |---------------------------------------|
     3 |    |    |    |    |    | #Kt|    |    |
       |---------------------------------------|
     2 |    |    |    |    |    |    |    |    |
       |---------------------------------------|
     1 |    |    |    |    |    |    |    |    |
        ---------------------------------------
         A    B    C    D    E    F    G    H

                Diag. 48

As soon as the Knight can obtain the King's support the game is
drawn even when the King is already forced on to the edge of the
board.

          Position--White: K at K6, R at K5
                    Black: K at K1, Kt at QR2

1. R-QB5, K-Q1; 2. K-Q6, Kt-B1ch; 3. K-B6, Kt-K2ch, draw. In this
case the King must avoid the corners, as the Knight would be
bereft of his efficiency.

          Position--White: K at KR6, R at KR4
                    Black: K at KR1, Kt at K2

1. R-K4, Kt-Kt1ch; 2. K-Kt6 and wins.

by Sas3 - 3 months ago
Hyderabad India
Member Since: Jun 2008
Member Points: 698

Great and timely (for me) lesson, Ron! Thanks a ton!!

I seem to be heading into one-such situation and I hope to put your lesson to use soon! Smile

by likesforests - 3 months ago
United States
Member Since: May 2007
Member Points: 3559

chesskia, it's carried by Amazon, Borders, and Barnes & Noble. It's by NEW IN CHESS and the title is "100 Endgames You Must Know" by Jesus de la Villa.

jaronkovich, glad you enjoyed. :)

by likesforests - 3 months ago
United States
Member Since: May 2007
Member Points: 3559

RaZhaN> Surviving on the Rim.. how is that a draw ? ... the knight is on a yellow square

RaZhaN, great questions.

In general, it's a forced win when (a) the knight is in the corner or (b) the knight and king are separated. Neither of those apply in the second example. In the yellow zone it's usually a draw with perfect play, but these positions are hard to hold and often humans--especially amateurs--make mistakes.

RaZhaN> on the 3rd one it is on a normal square yet it is captured

The 3rd example was more to illustrate how tricky this ending can get--and hence the need for the practice exercises--than any particular rule. But a knowledge of these rules would have helped them play better. Focusing on Black's perspective:

  • The initial position is lost for Black due to the knight in the corner.
  • 71...Ne5+?? - There are two reasons you should see this is wrong. First, it separates the N and K. Second, 71.Ne1+! is a draw similar to diagram 2.
  • 73...Nf6>?? - This further separates the pieces. 73...Nf2! regroups them.

Ultimately, 81...Nf6? made White's win a simple matter because it allowed the fork 82.Rf2!. You must watch for tactics in every phase of the game.

« Previous | 1 2 | Next »

Add your comment:

Join Chess.com for free to add your comment! Already a member? Then login now to comment.