Carlsen's Challenge Solved!

This was the pic that Carlsen posted on facebook asking us to solve his challenge. 

Here is a better board version of the problem:

http://sagarteacheschess.blogspot.in/2013/09/carlsen-challenge.html

To tell you the truth I spent quite a lot of effort on solving this one! Here you can see me trying it on the board. But my main efforts were made when I was jogging or travelling. The fact that there were just 8 pieces on the board meant that it was possible to try to go into complications blindfolded but the problem was not the number of pieces but the nice interweaving of ideas!
I would ask all those who have not solved this puzzle, dont look at the answer before giving it a shot. After all the depth of the problem can only be understood if you have tried solving it. Otherwise everything seems just so easy! :)

So the position was white to play and win.

White to play and Win

SOLUTION:

Of course the first move that comes to the mind of everyone is 1.Re3 now 1...Kb4 is forced and I guess 2.Rb3 looks the most natural 2...Ka4 3.Rb1 a2 4.Ra1 Ka3 5.Kd2 Kb2 6.c4! Ka1 7.Kc1

 (B)

Stalemating the black king in the corner and now only pawn moves remain. But black turns out to be a tricky person to deal with as he stops the c pawn right in its tracks with 7...d6! After this white just cannot win. 8.Kc2 a4 9.Kc1 a3 10.Kc2 d5 11.c5 (cd5 is stalemate) 11...d4 12.c6 d3+ and the best that white can get now is a draw.

HOWEVER IT WAS A START!

MANY OF THE PLAYERS THINK THAT SOLVING STUDIES MEANS TRYING TO FIND FLASHY MOVES RIGHT FROM THE GO. I DONT AGREE. YOU MUST ALWAYS BEGIN WITH THE MOST NATURAL CONTINUATION AND FROM THAT VARIATION GAIN IDEAS AND UNDERSTAND AS TO WHY YOUR MOVE DOESNT WORK AND THEN COME UP WITH THE IMPROVED VERSION OF THE ANSWER.

Its like developing an App. You develop an Application. Then you see the problems and fix the bugs. Then again develop the app further, fix the bugs. Its a continuous process till perfection is achieved.

So lets go back to the starting position. We learn a few things.

1. cutting off the Black King can be a great idea.

2. We will have to give up the rook but sacrificing it in such a way that black king will be stalemated is the key idea.

3. And we need our pawn on c5 so that in the position of stalemate, our pawn will be one step closer to queening.

 Its from all these deductions that we come up with the idea of 1.Re4!!

(B)

This move cuts off the black king from the 4th rank and also threatens Ra4. So the only move for black now is 1...Kb5. Now we push the pawn ahead with 2.c4+ and black will do well to advance further with 2...Kb4 (2...Kc5 is worse as now black king is behind in the race. 3.Re3 Kb4 4.Kd2 a2 5.Re1 Kb3 6.c5! the key move. 6...Kb2 7.Ra1! and we will come to almost the game continuation.)

So now that the rook and king are in the same line, we can push the pawn one square ahead with 3.c5! Kb3 (3...Kc5 4.Ra4 Kb5 5.Ra3 Kb4 Ra1 +-) 4.Re3 Kb2 and we reach the critical position of the study

 (W)

This is the most important position now. What do you do as white?

White has to come up with two consecutive strong moves now. the first one being 5.Kd3! the main idea of this move is to keep the second rank free for the rook to check. 5...a2 and now its time for 6.Re2!! 

This was really one of the toughest moves to think in this study. The idea of the rook check becomes clear once you see it. The rook would like to come to the first rank, but it wants to come without losing time. Usually we see such time gaining vertical checks in rook vs pawn. Here is a case of horizontal check! After this white gets two favourable things. he is able to set up a stalemate of black king and he has already got his pawn on 5th rank i.e c5.

6...Kb1 (6...Kb3 is similar) 7.Re1 Kb2

 (W)

Maybe for a trained eye the next move is not so difficult. But nonetheless it is beautiful!

White played the nice move 8.Ra1! Black can now push his a pawn, but it will not change anything and hence the rook is taken with 8...Ka1. and white stalemates the king with 9.Kc2

 (B)

Black has 2 ways to play now to push his pawn to a4 a3 or to first push his d pawn. Try to work out upto mate in both the variations.

Lets start with the d5 variation first.  9...d5 is met with 10.cd6! a4 11.d7 a3 12 Kb3! setting up a nice mate 12...Kb1 13 d8=Q a1=Q 14.Qd1 #

A nice mate!

So back to black's 9th move.

 9...a4 10.Kc1 a3 11.Kc2 d5 now taking the pawn will lead to stale mate and hence white must play 12.c6 d4 13.c7 d3+ 14.Kd3! Kb2 15.c8=Q a1=Q 16.Qc2#.

A beautiful mate. A small detail to notice is that if the pawn were not on a3, it would not have been a mate! Quite a coincidence eh!!

I am sure those who tried to solve this study found it not so easy. It was tough. But tougher the battle, sweeter is the victory. I was extremely happy after I solved this study. 

I hope you too enjoyed trying to solve this problem and looking through the answer. We must all thank Magnus Carlsen for sharing with us such a rich position with some excellent nuances and deep ideas!

As he is solving so many studies, I think we could expect some excellent ideas in the november match against our very own Vishy Anand!