Chess.com's Weekly Study: April 24th 2016

DailyFun

Hello Chess.com!

Starting with 2016, we will be posting a Weekly Study, courtesy of Yochanan Afek, Grandmaster for composing endgame studies. These challenging positions are designed to stimulate (and improve upon!) your creativity, depth of calculation, pattern recognition and pure imagination.

V. Kalandadze, 1970

Enjoy!

SaharanKnight

In the 1.Be5? line, I was looking at 2..Qh5+ rather, then 3.Kf5 (forced) Kh6. There isn't an analyze button to click to conveniently pursue this inferior line. However, it looks like the black queen would subsequently be challenged by the pawn promotion.

n9531l
SaharanKnight wrote:

In the 1.Be5? line, I was looking at 2..Qh5+ rather, then 3.Kf5 (forced) Kh6. There isn't an analyze button to click to conveniently pursue this inferior line. However, it looks like the black queen would subsequently be challenged by the pawn promotion.

I think you meant 2...Qh4+. It also draws, but is risky, since after 3.Kf5, Black might be tempted to play Kh6, which loses.

Seaslessspark

it is not so hard after all

limber_up

Very nice puzzle.

DailyFun

Next week's puzzle is ready:

https://www.chess.com/forum/view/chess-openings/chess-com-s-weekly-study-may-1st-2016

 

aakashmistri

Outstanding puzzle !!!!!!!

PJsStudio

Black may not have a draw with correct play but after the easily mistaken capture of the promoted queen this is a gorgeous puzzle.

lofina_eidel_ismail

this was good, and interesting too....will look him up (Y.Afek)

thx 

Arisktotle
DJsStudio schreef:

Black may not have a draw with correct play but after the easily mistaken capture of the promoted queen this is a gorgeous puzzle.

Your observation contains a contradiction. If black does not have a draw, then it is not a mistake to capture the promoted queen. All moves lose, so none can be a mistake. Notions of "other moves holding out longer" are considered completely insane (no exaggeration) by problemists. Such ideas are permitted on chess.coms Daily Puzzle and at no other place in the whole universe!

By the way, Afek makes sure that all studies are computer-tested. Black does lose indeed whatever he plays! 

PJsStudio

Well stated, although I was responding to the poster that proffered up that the capture of the queen was why the draw was blown.

Arisktotle

Surprising to see this one come back now. Haven't seen a new "Weekly Study" on this forum for months now. Did Afek go on World Tour? Did the DP-Staff forget to check his emails? High quality endgames and I liked them a lot!

n9531l

I agree with Arisktotle. This place hasn't been the same since the Weekly Studies stopped. To help Arisktotle stay sharp, here's a king and pawn ending for him to solve.

White to play and win.

SAGM001

Nice !

Arisktotle
n9531l wrote:

I agree with Arisktotle. This place hasn't been the same since the Weekly Studies stopped. To help Arisktotle stay sharp, here's a king and pawn ending for him to solve.

White to play and win.

Thx, n9531l! Really needed that. Lately my knife hasn't been cutting through the butter the way it used to.  I'll keep that one in the fridge till newyearsday and get it out for lunch. Light and nutritious I trust!

chesskingdreamer

@n9531l, do you recommend the study database for getting such problems?

n9531l

No, I prefer selecting from the 85,000+ studies in HHdbV.

Arisktotle
n9531l wrote: White to play and win.

Just know that Grigoriev's studies are never as easy as they seem. There is always another trick waiting in ambush! There are also a few duals in this one though.

 

n9531l

Would you say they are major duals or minor ones? And how do you tell the difference?

You should include the analysis of Black's main defense, 11...Kg6.

By the way, 3.Kd3 draws after Kh8 (assuming Black made the best move 2...Kg8).

Arisktotle

Ah I see. The first dual is not really a dual since 2. .. Kg8 is a bit better than 2. .. Kf6. I only counted on black  moving on to h7 next but he can of course return on his ways as well, leading to the main line.

The Kd3 dual would have been the worse of the two since it is the blunt change of move order that composers don't like. The second dual is a minor one as it delays the main solution line by one move. This type of dual is quite common and is probably the main reason that a puzzle interface must be capable of handling correct alternatives. You can't punish a solver for chosing the longer route; it's not a mating assignment.

I mentioned the 11. .. Kg6 defense in the analysis but I didn't pursue it because we entered modern endgame theory. Even if Grigoriev found an efficient solution to this Q+P vs Q (+2 distant pawns) ending, there may be other solutions that Grigoriev would never have considered. Only a few decades ago, theorists believed that most Q+P vs Q endings were drawn but the tablebases changed all that. I therefore left this analysis alone. I presume I would receive full marks in a solving contest when stopping at this point but, on your request, I added a "for instance" line to the analysis. Edit: I do not have the 7-piece tablebase to check whether or not there are alternative wins for white in the queen ending but i suppose you can see that.