Pandolfini's Puzzler #59: A Knight Can Stop a Pawn

Professor: Hello, class.

The class offered a measured blah response. Rachel then spoke up.

Rachel: What’s planned for today, Professor?

Professor: I thought I’d throw it open to the class.

Lucian: How about showing what three minor pieces can do against a queen?

Professor: Maybe, but not today.

Hale: What about knights stopping passed pawns?

Rachel: Yeah, like when the defending king can’t help out.

Professor: Actually, that’s not a bad idea.

Lucian: Especially facing a pawn on the 7th rank.

Thomas: That situation can be problematic.

Professor: Okay. Let’s see a defining example to start with.

Question 1: Can White force a draw?

The kids rapidly got the answer. They wanted more.

Lucian: Okay, that’s a center pawn. What about a bishop pawn?

Professor: Sure, but let’s widen the concept a bit.

Zephyr: Don’t get too wide. The board has only 8 files.

It was the Professor’s turn to smile.

Question 2: Does White have a draw?

The analysis went awry, but led by Idris, it quickly got back on track.

Rachel: We started with an errant knight move, but Idris found the right way.

Zephyr: Yeah, he usually does.

Lucian: That was a bishop pawn. How about a knight pawn?

Professor: Coming up.

Question 3: Can White draw?

This required greater deliberation, but the class worked it out nicely.

Thomas: I like the team effort of the king and knight.

Ryan: It’s amazing how resourceful the knight can be.

Professor: But you know, sometimes the knight pawn can present a problem.

Zephyr: What do you mean, Professor?

Professor: Well, check out this next position.

Question 4: Can White to move draw?

The class soon realized the difficulty. Even with the move, White was lost.

Ryan: It’s funny. Rook pawns can cause stress. But knight pawns often pose their own special problems.

Hale: Clearly, that’s true in many types of endings.

Idris: Pro and con.

Professor: Good points. Let’s turn our attention to the rook pawn.

Zephyr: Let’s.

Question 5: Can White to move draw?

With predictable repartee, the class found how the knight could reposition to stop the pawn. But the call was for something more complicated.

Rachel: Do you have anything a twinge bit harder?

Professor: Well, here’s a final challenge. Let’s see what you do with it.

Question 6: Can White hold a draw?

Ryan: Doesn’t Averbakh analyze that problem somewhere?

Professor: Actually, it’s analyzed all over the place.

Idris: Grigoriev composed several positions like it.

Professor: Very good, very true.

Lucian: So what can we conclude about this session?

Zephyr: That it’s time to go home?

Professor: Now that’s a fitting conclusion indeed.

Answers below -- Try to solve NM Pandolfini's puzzles first!

Answer 1: White draws with 1. Nc2+ Kd2 (on 1…Kd1 the knight shifts to the other side of the pawn, 2. Ne3+ Kd2 3. Ng2) 2. Nd4! e1/Q 3. Nf3+, and the forking check gets the new queen.

In general, a knight, without immediate support of its own king, can stop an advancing pawn if:

(1) it can safely occupy any square in the pawn’s path (with the possible exception of the rook-eight square); or

(2) it has a forking check after promotion.

Answer 2: The draw is achieved, not by 1. Nc1+? Ke3, but by 1. Nb4+ Ke3 (on 1… Kc3 White has 2. Ke2) 2. Nc2+ Kf3 3. Ne1+!.

Answer 3: This is a little trickier. The main line is 1. Kf5 g2 2. Ng5+ Kg3 3. Ne4+ Kh2 4. Ng5, when no progress can be made, since 4…g1/Q is met by 5. Nf3+.

Again, White saves the day with a forking knight check after promotion.

Answer 4: Even with the move, White can’t hold against this particular knight-pawn alignment. The key line is 1. Ne2+ Kf1 2. Ng3+ Ke1!, and White is unable to shift to the square i2, there being no i-file and no i2-square.

Answer 5: A little shift holds the fort. White draws by 1. Nd3+ Kd2 2. Nb4 (getting on “the circuit”), when 2…Kc3 3. Na2+ Kb2 4. Nb4 Kb3 5. Nd3 a2 is met by the forking check 6. Nc1+.

Answer 6: In this position, analyzed by Grigoriev, Averbakh and others, the draw is achieved with 1. Kb6 Ke5 (1…Ke3 2. Nf1+) 2. Kc5 Kf4 3. Nh1 Kf3 4. Kd4 Kg2 5. Ke3 Kxh1 6. Kf2 stalemate.

It’s curious how the knight directly and indirectly sets up a barrier, consisting of the squares d2, e2, e3, and e4.

Take note:
There are many studies involving a knight against a lone pawn or several pawns. They can be quite illuminating, with great practical significance. To be sure, before transitioning to certain endgame positions, it can be handy to know how effectively a knight can deal with menacing pawns.

Vital questions concern whether a knight can get back in time to stop a successful promotion and, once close enough, how well the knight can fend off the enemy king.

If you want to explore the subject further, both “D’voretsky’s Endgame Manual” by Mark D’voretsky and “Fundamental Chess Endings” by Karsten Müller and Frank Lamprecht provide excellent material, with clear and pragmatic explanations.