Rajdeep's impeccable decision!

The International Grandmasters tournament has begun in Kolkata today. The tournament is extremely strong as can be witnessed from the starting list.

There are 131 participants with an Elo average of 2287! Quite impressive!

A tournament where a former World Championship finalist participates is bound to get international attention. Nigel Short in the centre with the chief organizer Dibendyu Barua and Abhijit Kunte. (picture credit: Abhijit Kunte's world famous selfies!)

Just as the round started, Asim Periera, the founder of follow chess app, made the following tweet:

Wow did Nigel Short @nigelshortchess really play 1. f3 2. g4!! Unbelievable. #KolkataChess pic.twitter.com/om7IuBfLoS
— Asim Pereira (@asimpereira) March 16, 2015

But he soon realised that even for the bold and brave Nigel, this was crossing the limit!

Ok that was a false alarm. The Arbiter might have been testing the live transmission! @nigelshortchess #SanityRestored
— Asim Pereira (@asimpereira) March 16, 2015

Mostly all of the top seeds won their games with relative ease, though I must mention that Abhimanyu Puranik scored a super upset by defeated Ortiz Suarez (2625) who was rated almost 350 points above him. 

GM-killer: Abhimanyu Puranik. (picture by Amruta Mokal)

Though this was the result of the day, my attention was caught by another game that was also played by a young Indian on the adjoining board. Rajdeep Sarkar was up against the 2600+ Cuban GM Quesada Perez. After 47 moves, the following position was reached:

Quesada Perez vs Rajdeep Sarkar. White to play

Black's last move was Nb7-d6 offering White the option of entering a king and pawn endgame. Was this a wise decision or do you think it was some kind of a suicide? What is your opinion?

SOLUTION

Offering the exchange of knights looks like a very poor decision by the black player. After all he has the doubled c-pawns and White has the passed e-pawn. But it turns out that this young Indian who is just 15 years old had calculated his chances to perfection.

The cool and calm: Rajdeep Sarkar 

Quesada immediately exchanged the knights with 48. Nxd6 Kxd6 and we reach the following king and pawn endgame.

In order to make progress, White has to take the g3 break, If he just plays Kg4 then after Ke5 Kxh4 Kxe4 Kg5 Kd3 Kxg6 Kxc3 , Black is very quick and in fact makes his queen before White does. Once you realize that the g3 break is imperative, then the next phase of the game becomes easy to understand. Here are the moves:

White has made a queen and Black has pushed his pawn to c2. It's White to play.

It is a basic rule in queen vs pawn on the 7th rank endgame that if the pawn is a bishop pawn, then the position is drawn. But first we must check if the White king isn't too near. If it is, then he can take part in mating the black king.

The rule in such endgames is the following: If the Black king is on the long side of the bishop pawn, White is winning if his king is two squares away from the e2 square.

The winning zone for the White king. Notice that all the green squares are two or less moves away from the crucial e2 square.

If you notice the game position, you will realize that the White king which is on g5 is just outside the box. Hence in this position, the White king is not going to be useful. The White queen has to do all the damage. 

If Black had just the pawn on c2 and no pawn on c5, we wouldn't have to discuss this position at all. It would have been an easy draw. The reason for that is the following. Let's just remove the c5 pawn and get the following position on the board.

All that we have done is we have removed the c5 pawn from the game position. Now let's see the drawing procedure.

And it's a stalemate! Most of you must be well acquainted with this technique of playing the king to a1 and letting the queen take the pawn to create a stalemate pattern. Now let us just randomly add a pawn, say on c7, and study the same position again.

With an extra pawn on c7, this endgame is winning for White because Black cannot try the stalemating pattern. This is the winning procedure:

You see, with an extra pawn, this turned out to be an easy win for the side with the queen. Let us come back to the position of the game between Quesada and Rajdeep.

So, was Rajdeep's decision to go into this endgame wrong? After all the extra pawn on c5 will not allow him to create the stalemating ideas.

As it turns out the c5 pawn doesn't allow the stalemate but it also doesn't allow Qb4+. This is a very important check. If the queen is not given this opportunity of checking from b4, then it is impossible to gain control of the b3 square. If the b3 square cannot be controlled then the black king cannot be pushed into the corner. Have a look at how the game progressed:

This is the crucial position that I was talking about. Now the Black king moves to b2. If the pawn were say somewhere on g7, h7, h5 etc. instead of c5 then the white queen would give Qb4+ and after Ka2 Qc3 Kb1 gain the access to the all important b3 square with Qb3+ winning the game. The c5 pawn is extremely important for not letting the white queen give the all important check on b4.

Quesada Perez tried for a few more moves before conceding the half point. This is how the game ended.

Picture credit: Amruta Mokal

Something that I find truly amazing is that Rajdeep was able to assess this endgame correctly when he played the knight to d6 and offered his opponent to enter the king and pawn endgame. This shows a deep knowledge of endgames. Hats off to the little kid and I hope that he keeps up this good form in the tournament.

Quesada Perez Yuniesky got a taste of some very high endgame knowledge from his much lower rated opponent in the first round itself!

(Special thanks to Ketan Patil who discussed a similar queen vs pawn endgame with me a few months ago.)