Friday, May 15, 2020

K+Q vs. K+R: How to Win This Tricky Ending

Click here if the diagrams aren't displaying correctly

Over the last few weeks, I have been exploring ChessTempo's Endgame Benchmark problems. Most of them weren't too hard and my rating rose steadily. But then I ran into a bunch of Queen vs. Rook exercises. They were extremely difficult. I don't think most players realize how tough they are. Successfully solving them would often take more than an hour plus a bit of "luck." (I.e., the computer playing a move that delays checkmate but is easy to refute). In a practical game, this could be even harder. The defensive techniques are very simple, you won't have hours and hours of time on the clock, and you'll be exhausted from the long battle that preceded the endgame. So here is my guide to winning this tricky ending.

Tip #1: *Always* watch out for stalemate

I was working on a problem, and the following position came up in my calculations. You can quickly verify that there is no safe square for the rook. Either it falls immediately or it falls a few moves later due to tactics. I was about to head for this position, but then I remembered to look for stalemate.

[Event "?"] [Site "?"] [Date "????.??.??"] [Round "?"] [White "New game"] [Black "?"] [Result "*"] [SetUp "1"] [FEN "8/8/1Q6/8/k7/8/1K6/2r5 b - - 0 1"] [PlyCount "1"] 1... Rc5 $1 {and the rook is immune. White's pieces don't coordinate very well and the win will be difficult.} *



The next position is well known.


[Event "?"] [Site "?"] [Date "????.??.??"] [Round "?"] [White "New game"] [Black "?"] [Result "*"] [SetUp "1"] [FEN "5k2/7r/4Q1K1/8/8/8/8/8 b - - 0 1"] [PlyCount "3"] [TimeControl "40/7200:20/3600:1800"] 1... Rg7+ $1 (1... Rh6+ $1 {also works}) 2. Kf5 (2. Kh6 Rh7+ $1) (2. Kf6 Rg6+ $1 {This idea is especially important to know. It comes up in a lot of variations}) 2... Rf7+ {The only way to escape the checks is to play 3.Ke5 or 3.Ke4. But in either case, Black draws immediately with 3...Re7.} *



Tip #2: Centralize the queen

We all know that a centralized queen controls more squares than a cornered queen. Thus, if you keep your queen in the center, she can often pick off the rook with a fork. So far I'm just stating the obvious. But if you combine the first 2 tips, you may learn something new: when you push back the defender, lead with your king, not your queen. To see this, change the last diagram just a little.


[Event "?"] [Site "?"] [Date "????.??.??"] [Round "?"] [White "New game"] [Black "?"] [Result "*"] [SetUp "1"] [FEN "5k2/7r/6K1/3Q4/8/8/8/8 b - - 0 1"] [PlyCount "4"] {The situation is completely different.} 1... Rg7+ (1... Rh6+ {doesn't work any more. Because White kept his queen in the center, there are no stalemates.} ) (1... Re7 {(to prevent 2.Qd8#)} 2. Qd8+ Re8 3. Qf6+) 2. Kf6 Re7 ({ Another important difference:} 2... Rg6+ {isn't stalemate. Again, there are no stalemates because the queen stayed in the center.}) 3. Qd6 {and the rook falls } *



Tip #3: The Temporary Retreat

At first, it's easy to push the defender back. The tough part is once they are near the edge, it's hard to make further progress due to stalemate threats. The defender should keep the rook on the third rank. This simple idea will probably frustrate the attacker unless he knows about the Temporary Retreat.


[Event "?"] [Site "?"] [Date "????.??.??"] [Round "?"] [White "New game"] [Black "?"] [Result "*"] [SetUp "1"] [FEN "8/8/8/8/3Q4/1k1K4/8/2r5 w - - 0 1"] [PlyCount "3"] [TimeControl "?"] 1. Qe5 $1 (1. Qb6+ {is tempting, since it pushes back the enemy king. But White's king cannot approach and there's no way to fork the rook.}) 1... Rd1+ 2. Ke2 {At first glance, White is losing ground. But Black's blockade quickly collapses. The rook can't hold the d-file because of forks (I'll let you work out the details). Trying to give checks from the side with 2...Rg1 or 2...Rh1 fails for the same reason. Returning to the c-file doesn't work either: 2... Rc1 3.Kd2 and the checks end shortly. The rest is straightforward.} *



Thus, the Temporary Retreat is very effective. However, it's so counterintuitive that you probably wouldn't find it during a game. Voluntarily giving up ground looks is very unnatural; almost everyone will prefer 1.Qb6+ instead and then struggle to break the blockade. Now there is one more paradoxical idea to know, which brings us to Tip #4.


Tip #4: Letting the King escape


[Event "?"] [Site "?"] [Date "????.??.??"] [Round "?"] [White "New game"] [Black "?"] [Result "*"] [SetUp "1"] [FEN "8/8/8/4Q3/8/k2K4/1r6/8 w - - 0 1"] [PlyCount "25"] 1. Qa5+ {My first instinct was to approach with the king, but then I just get checked. So instead, I intentionally let Black's king escape from the a-file.} Kb3 2. Qa1 $3 {And now I violate Tip #2 and put my queen in the corner. At first, White's last 2 moves look terrible. But let's look deeper. While Black's king did escape from the a-file, he can't run any further - he's chained to the rook. Furthermore, the Black king is taking away squares from the rook. Black's pieces are badly misplaced and he's in zugzwang.} Rh2 (2... Ra2 3. Qc3+ Ka4 4. Kc4 {and it's very easy}) 3. Qc3+ Ka2 (3... Ka4 4. Qd4+ $1 { (centralization) and the rook drops off shortly:} Kb3 { (other moves lose the rook even faster. I'll let you verify)} 5. Qd5+ $1 Ka4 { (again, other moves lose the rook more quickly)} 6. Qa8+ $1 { followed by 7.Qb8+ and 8.Qxh2}) 4. Qe5 $1 {Centralizing the queen. It's hard to believe, but White can't fork the rook yet. Instead, I take away squares and prepare to advance my king.} Rb2 (4... Rh3+ 5. Kc2 { and the centralized queen denies Black ...Rh2+}) 5. Kc3 Kb1 { The rook can't move because of tactics} 6. Qe1+ Ka2 7. Qd1 $1 ({ Remember our earlier principle: lead with the king, not the queen.} 7. Qc1 $6 Rb3+ {and now White can't play} 8. Kc2 $4 {because of} Rc3+ $1 {. So White has to play 8.Kc4 and then he's driven back even further after 8...Rb4+!}) 7... Rh2 {Black is in zugzwang; all the rook moves lose quickly.} 8. Qa4+ Kb1 9. Qb5+ Ka2 10. Qa6+ Kb1 11. Qb6+ Ka2 12. Qa7+ Kb1 13. Qb8+ { winning the rook and the game} *



And that is how you win Queen vs. Rook. Stay healthy everyone!

1 comment:

  1. Tip #5: Quiet moves trump checks. Of course, this isn't always true. If you see a sequence of checks that win the rook, go for it. But I often find that checks don't get me anywhere. Taking a tempo to centralize the queen is usually more effective.

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