Can You Calculate Like a U.S. Championship Contender?

A pivotal moment of the championship—Hikaru Nakamura resigns against Fabiano Caruana. Photo courtesy of Lennart Ootes.

At the halfway point of the U.S. Championship, two favorites, Fabiano Caruana and Wesley So, lead while Ray Robson trails by half a point.

The defending U.S. Champion, Hikaru Nakamura, trailed by a point (along with Jeffrey Xiong and Alexander Onischuk) since he lost to Caruana in the 4th round.

Test your calculation skills with these tactics from decisive moments in the championship.

Jeffrey Xiong---Undefeated so far Photo courtesy of Austin Fuller.

Tactic #1

Jeffrey Xiong vs. Gata Kamsky

After tense middlegame battle between the prodigy and the veteran---with both sides vehemently fighting for the upper hand, Kamsky blundered in an equal position. How did Xiong score his first victory of the championship?

Position after 36...Oxf3

White to move.

Level: Easy

Show Solution

"The defensive power of a pinned piece is but imaginary." -Aron Nimzowitsch

Show Solution

[pgn][White "Jeffery Xiong"]
[Black "Gata Kamsky"]
[Result "1-0"]
[ECO "B03"]
[WhiteElo "2618"]
[BlackElo "2678"]
[SetUp "1"]
[FEN "3r4/1p3pkp/6p1/Pp6/3p4/1P1RnqP1/3Q3P/4R1K1 w - - 0 37"]
[PlyCount "5"]
[EventDate "2016.04.13"]37. Rexe3 (37. Rxd4 {also wins}) 37... dxe3 38. Qb2+ {A devastating intermezzo
(in-between move). Kamsky resigned.} f6 39. Rxd8 1-0[/pgn]

Tactic #2

Fabiano Caruana vs. Hikaru Nakamura

How did Caruana get the better of Nakamura in the battle between the top two Americans?

Position after 27...h3

White to move.

Level: Intermediate

Show Solution

"Every student hears tall tales of grandmasters who can look 10, 15 or 20 moves into the future. A GM annotating one of his games may claim he visualized the winning ending while he was still in the early middlegame. Or when he was in the late opening. Or when he was having breakfast that morning.

Most of the time you can find a good move - if not the best move - with a low level of calculation. How low? Two and a half moves into the future."

-Grandmaster Andrew Soltis

Show Solution

[pgn]
[White "Caruana, Fabiano"]
[Black "Nakamura, Hikaru"]
[Result "1-0"]
[ECO "B90"]
[WhiteElo "2795"]
[BlackElo "2787"]
[SetUp "1"]
[FEN "1k5r/1p2b3/p2p4/3Bp3/bq2Pp2/R6p/1PP2QPP/5R1K w - - 0 28"]
[PlyCount "7"]
[EventDate "2016.04.14"]
[EventType "tourn"]
[EventRounds "11"]
[EventCountry "USA"]
[EventCategory "17"]
[Source "Mark Crowther"]
[SourceDate "2016.04.18"]28. c3 {All of the Black queen's escape squares hang or immobilize the Black
bishop.} Qb5 (28... Qa5 29. Rfa1) (28... hxg2+ 29. Qxg2 {doesn't change
anything.}) 29. b3 Bh4 30. bxa4 Qd3 (30... Bxf2 31. axb5) 31. g3 {and Nakamura
resigned.} 1-0[/pgn]

Tactic #3

Alexander Onischuk vs. Aleksandr Lenderman

Position after 23...Qb6

White to move.

Level: Advanced

Show Solution

"Calculation without a goal is wasted."

-Grandmaster Jonathan Hawkins, Amateur to IM: Proven Ideas and Training Methods

Show Solution

[pgn]
[White "Onischuk, Alexander"]
[Black "Lenderman, Aleksandr"]
[Result "1-0"]
[ECO "D10"]
[WhiteElo "2664"]
[BlackElo "2618"]
[SetUp "1"]
[FEN "6nr/ppr2pkp/1q4p1/1B6/1B1bR3/1Q6/PP4PP/5R1K w - - 0 24"]
[PlyCount "5"]
[EventDate "2016.04.14"]
[EventType "tourn"]
[EventRounds "11"]
[EventCountry "USA"]
[EventCategory "17"]
[Source "Mark Crowther"]
[SourceDate "2016.04.18"]

24. Re6 $3 {A very difficult move to spot, even though the concept is rather
simple: The white rook is untouchable because the f7-pawn is pinned to
checkmate. Black's queen is under attack and has no safe square to escape to.}
({Although Onischuk missed 24. Re6, he found a strong alternate continuation:}
24. Rxd4 Qxd4 25. Bc3 {and went on to win after:} Rxc3 26. bxc3 Qd6 27. Qxf7+
Kh6 28. Qf8+ Qxf8 29. Rxf8 Kg7 30. Rb8 b6 31. Rb7+) 24... Qxb5 (24... fxe6 25.
Bf8# {A rare checkmate pattern.}) 25. Bf8+ Kxf8 26. Qxb5 1-0[/pgn]

Live games and commentary by GM Yasser Seirawan, WGM Jennifer Shahade, and GM Maurice Ashley are featured at the U.S. Championship Official Website. Rounds are everyday at 1 p.m. CST from April 14th-April 26th.