Saturday, May 03, 2014

Complicated chess tactic



White to move. Is this a win, loss, or draw for White? No computer analysis please.

6rk/p5pn/6Q1/3p4/5NP1/7P/P4PK1/3q4 w - - 0 3

17 comments:

Yancey Ward said...

I remember this puzzle very, very well, even 4 years later. This one stumped me the first time around- even the incorrect solution I offered I misjudged as a draw (white actually loses with best play).

Once you find white's only move, there are two main lines depending on black's first move response.

Anonymous said...

Raked my brain for a long time, but then I got a headache, so had to resort to the computer lol

A very interesting puzzle indeed! Got to think laterally.

Patrick

pht said...

Here is an obvious choking mate motive, and one logical looking move is Qf7. There are traps:

1. Qf7 Ng5??
2. Qh5+! Nh7
3. Ng6#

1. ... Nf8??
is the same.

However: Nf6 or (more natural) g5 both look pretty good for black.

Jaya Chandran Devarathnam said...

Best line
1. Qh5 g6
2. Qe5+ Rg7
3. Ng6+ Kg8
4. Qe8+ Nf8
5. Qf8+

Anonymous said...

Qf7 with a threat Ng6

Sergio Fonseca said...

Qb1, following mate with knigth or giving the queen (to save the mate -
sergio

Sergio Fonseca said...

Qb1. To save the mate ( Ng6) - black hás to give the queen, by playing g5 for instante.
Sergui

Yancey Ward said...

So far, these are all wrong.

Anonymous said...

With best play on both sides it is a draw!White has to take the perpetual, else he loses!
1.Qf5!!.

A-1...g6.2.Qe5+.Nf6!(If Rg7 then Ne6 & white mates; throwing in the Q & N later only delays) 3.Qxf6+.Kh7!
4.Ne6 (threatening Qh5#) black has 4...Qd2! and white has to take a perpetual with either
>>A11-5.Qh5+.Qh6.6.Ng5+.Kg7.7.Ne6+Kh7! >>A12-5.Qf7+.Kh8.(not.5...Kh3.6.g5+ threatening 7.Qh7# and winning the black queen)6.Qf6+

Alternative B is practically the same as A.
B-1...g5.2.Qe5+.Nf6!(If Rg7 then Ne6 & white mates; throwing in the Q&N later only delays)3.Qxf6+.Kh7!
4.Ne6 (threatening Qf7+ & Qh5#) black has 4...Qd3! to interpose at h7 and hence white has to take a perpetual with
5.Qf7+.Kh8!.6.Qf6+.Kh7, etc. Note that here 5...Kh3. appears dangerous for black. 6.Qxg8. but i think black can take a perpetual with 6...Qe4+ and white king cannot escape checks.

Harry

Anonymous said...

1.Qf5! and it is a draw with best play!
Black is forced to give up his N to prevent mate but both will have to agree to perpetuals; otherwise they lose!
I wrote a detailed solution but it is not appearing; maybe it will be posted later after moderation.

Harry

Yancey Ward said...

pht,

Black has options after 1.Qf7, but the clearest is

1. Qf7 Qf3!
2. Kg1

If white takes the queen, black forks the king and queen from g5 with the knight to regain the material. Continuing:

2. .....Nf6
3. Ng6 Kh7
4. Ne5

If 4.g5, then black plays Qh5. Continuing:

4. .....Qe4 and if white can hold this down a rook for a pawn, I don't see it.

Yancey Ward said...

The first time around on this puzzle, I was convinced white held a draw with 1.Qh5, and I thought that was the best white could do, but I overlooked black's obvious defense:

1. Qh5 g5! (the only winning move)
2. Ng6 Rg6 (Kg7 look ok??)
3. Qg6 Qd4

And now, down a knight for a pawn, white must try for draw by repetition:

4. Qe8 Kg7
5. Qe7 Kh6
6. Qe6 Nf6
7. Qf7 a5 (freeing the queen)
8. Qf8 Kg6

And the knight can now protect the king against all by himself- the knight guards e8, g8, and h5- this is a common defensive motif with the king and knight on adjoining squares. There are other lines, of course, after 3. ...Qd4, but they should all eventually reduce to the same sort of defensive posture- white can't really prevent it.

Yancey Ward said...

Finally, as for 1.Qb1, one overlooks that after Q takes at b1, the black queen guards the g6 square. The same applies for 1.Qd3.

Anonymous said...

1. Qe4! Nf8 (else, see Harry's comments) 2. Qf5 g6/g5 3. Qf6+ and it ends with perpetuals.

B.A. said...

1. Qe4 Nf6 or Ng5 2. Ng6 Kh7 3. Nf8 with a mate
1. ... g5 or g6 2. Qe5 Rg7 3. Ne6 with a mate
1. ... Rf8 2. Ng6 Kg8 3. Qe6 Rf7 4. Ne7 and again Ng6 - here I cannot find a win
1. ... Rd8, Rc8, Rb8, Ra8 2. Ng6 Kg8 3. Qe6x
1. ... Re8 2. Ng6 Kg8 3. Qe8x
1. ... Nf8 2. Qf5 g5 or g6 3. Qf6 to be further analyzed

psyche said...
This comment has been removed by the author.
psyche said...

Given that all postings have been incorrect according to Yancey, I'm posting a continuation that I "solved" the first move within 30 seconds, but then discovered after analysis that there was only a drawn variation in one line. There is one line (line 3) that draws; lines 1 and 2 win for white.
A. Clearly a key is the potential N checkmate at g6, but also in other variations possibly e6.
B. So the Q must move but should retain the b1-h7 diagonal so if the Black Knight moves without covering g6 e.g. to f6, the check 2. Ng6+,Kh7 3. Nf8 double + and 4. Qh7+ N*h7 5. Ng6#
C. Where should the Queen then go?
Only Qf5 or Qe4 are available (cannot be taken at e4 as Ng6 mate). Both allow the critical e5 check if the Black g pawn moves, but e4 also controls the e file. I find Qe4 more versatile. Obviously 1. Qe4, d5*e4 loses to Ng6 mate.
Additionally, I think 1. Qf5 loses simply to Re8. White has to command the b1-h7 diagonal and the e file to win. So ultimately the only try is e4.
Three lines:
First line: Black rook moves and black loses.
1. Qe4 Rb8, 2. Ng6, Kg8 3. Qe6#
Second line as above: Knight moving not to Nf8
1. Qe4 Nf6 2. Ng6+,Kh7 3. Nf8+ and 4. Q mates
Third line: Black knight covers the critical square, but after 2.Qf5 has lost a tempo.
1. Qe4, Nf8 covering g6.
Now white has two options:
If 2. Qe5 threatening h5 and mates and pinning the g pawn. But then 2… Q c2; so it may be that Qf5 is clearer.
If 2. Qf5 threatening h5 and mates, keeping the diagonal but not pinning the g pawn; then g4 3. Qf6+ Kh7 but it appears to be a draw e.g. by perpetual though 4. Nh5 and 5. Qf7+; if 4. …Nd7 to prevent the perpetual, then 5. Qf7+ Kh1 6. Q*d7 with a likely draw as black will have to give up the exchange, will be a pawn down but with queens as the only pieces on the board.

Psyche