Chess

A 10-Player Logjam at a High-Stakes Event

By DYLAN LOEB McCLAIN

Published: July 27, 2013

The World Open has been the biggest tournament in the United States for four decades, the draw being the hundreds of thousands of dollars in prize money.

Position after 18 Re1; click to replay

Position after 16 … Na4; click to replay

When this year’s tournament, in Arlington, Va., ended three weeks ago, 10 grandmasters tied for first in the top section, with Varuzhan Akobian, an American, taking the title by winning an Armageddon game playoff. The 10 leaders included four other Americans, two players from Cuba, one from India, one from the Czech Republic and one from Georgia.

Such a logjam had happened only three times before, most recently in 2003.

With that quality of competition, entertaining games were guaranteed. One of them was in Round 7, when Tamaz Gelashvili, a grandmaster from Georgia who was among those who tied for first, defeated Ray Robson, an American grandmaster.

In the top diagram, Gelashvili took a pawn with 18 ... Qb2. So Robson decided on an all-out attack, beginning with 19 g5. The game continued 19 ... Nh5 20 Bc7 Ng7 21 Rb1 Qa3 22 Ne4 Qa4 23 Re1 Qa2 24 Bd6 Qb2 25 Bf8 Nf8 26 Qf4.

Gelashvili avoided 26 ... Qd4, when he would have lost his queen after 27 Nf6. Instead, he played 26 ... Be6, and the game went 27 Nf6 Kh8 28 Qh4 a4 29 Re4 a3 30 Qh6 a2 31 Rh4 a1/Q 32 Kh2 Nh5 33 Rh5 gh5 34 Nh7 Nh7 35 Be4. Gelashvili seemed to be in real trouble.

But he saved himself with 35 ... Qg1, a spectacular move in which he sacrificed his queen. After 36 Kg1 Qc1 37 Kh2 Qf4, Robson resigned. If he had played 38 Kg1, then 38 ... Qg5 would have forced a trade of queens, the attack would have been over, and he would have been down a rook in material.

Another Round 7 game with a white-knuckle finish was between Alexander Shabalov, a four-time United States champion, and Bogdan Vioreanu, an international master from Romania.

In the bottom diagram, Shabalov, who loves to attack, sacrificed an exchange by playing 17 Ra3, which allowed 17 ... Ba3. After 18 ba3, Vioreanu played 18 ... Kd8 in an attempt to remove his king from danger.

The game continued 19 Nd6 Rf8 20 Qh7 Kc7 21 Ndf7 Nac3 22 Re1 c5 23 dc5 Ne7 24 Ne6 Qe6 25 Ng5 Qd7 26 e6 Qe8 27 Nf7 Bg2 28 Bf4 Kc6 29 Kg2 Kc5 30 Qg7 Ned5 31 Bd6 Kc6 32 Bf8 Qf8 33 Ne5 Kd6 34 Qd7 Kc5 35 Qc6 Kd4 36 e7 Ne7 37 Qb6 Kd5 38 Nd7, and Vioreanu resigned.

The only way he could have stopped the immediate threat of 39 Qc5, mate, and not lose his queen would have been to play 38 ... Qc8. But then the game could have concluded 39 Qe6 Kd4 40 Qe5 Kd3 41 Qe3 Kc2 42 Rc1 Kb3 43 Qc3 Ka4 44 Qb4, mate.

A version of this article appeared in print on July 28, 2013, on page A19 of the New York edition with the headline: A 10-Player Logjam At a High-Stakes Event.