U.S. Champs R6: Robson Takes Down So; Nakamura, Nemcova Hold Lead

GM Ray Robson moved into clear second on Tuesday, after taking down his former Webster University roommate and World Top-10 GM Wesley So. // Lennart Ootes Photo

By FM Kostya Kavutskiy

The lone rest day on Monday was put to good use, as recharged players returned Tuesday for Round 6 and produced some of the most interesting games so far in the 2015 U.S. Chess Championship. GM Hikaru Nakamura wasn’t able to outplay GM Sam Shankland in a tense battle, but his first-place standing was helped greatly by GM Ray Robson, who turned the tables in mutual time pressure to defeat former Webster teammate and roommate GM Wesley So. As a result Hikaru, holds the lead with 4.5/6, while only Robson trails by a half-point in clear second.

2015 U.S. Championship Rankings After Round 6

In the 2015 U.S. Women’s Chess Championship, WGM Katerina Nemcova continued stellar play with her fourth win of the event, moving to 5/6 after overcoming WFM Jennifer Yu with the Black pieces in Tuesday’s sixth round. Adding to the drama, GM Irina Krush spoiled a huge opportunity against WGM Anna Sharevich, missing several chances to win before allowing perpetual check.

2015 U.S. Women's Championship Rankings After Round 6

2014 Chess Olympiad gold medalist GM Sam Shankland showed no fear of World No. 2 GM Hikaru Nakamura in Tuesday's sixth round. // Lennart Ootes Photo

Judging by the opening, Tuesday’s highlight game looked to be Nakamura vs. Shankland, as the two players engaged in a dynamic Advance Variation of the Caro-Kann Defense. Shankland showed no fear of the World No. 2, first castling queenside and then offering a pawn with 13…Ng6.

“I played badly I think -- it’s not so much the moves I played but the way I used my time,” Nakamura vented. “I think 12. f4 was just kind of stupid to play, when I basically used 20 minutes on the last two moves. To go into something that can be very messy is rather stupid at this point of the tournament, especially against one of the stronger players that I have to play.”

After the strong moves 17…f5 and 18…Nf6, Shankland found the upper hand in the encounter, but failed to increase his advantage and instead entered an endgame where White stood better. However, it was Nakamura who missed his chance, overlooking 29.Nc5!, which would have put extra pressure on Shankland’s defenses. The players agreed to a draw a few moves later, after Nakamura’s winning chances had fizzled.

GM Ray Robson trails leader GM Hikaru Nakamura by only a half-point after six rounds at the U.S. Championship. // Kevin Duggin photo

Robson vs. So using the Berlin Defense was labelled a “snooze-fest” by the commentators (with most GM-level games in the same variation ending in draws). That all changed, however, once Robson played 16.d5 for an interesting pawn sacrifice.

“I know Wesley, I know how good of a player he is, but with White it was going to be hard for him to hurt me,” Robson said. “I was just trying to play normal moves and, if I got an advantage where I could press, then I would try [to win]. But otherwise if he plays very solidly, a draw would be OK.”

Despite Robson’s plan of playing it safe, things turned extremely messy after Wesley’s 23…Rb8, giving back the pawn in order to generate counterplay of his own. Three moves later, Robson sacrificed the exchange with 27.Rxe5!?, a huge risk considering both players were already in serious time trouble.

“Honestly, I think [27.Rxe5] was the best move in the situation,” Robson said. “I think I let the position get a little bit out of hand, but I still thought that I have these really strong pawns on the queenside, and my bishop is really strong as well.”

Though the computer gave Wesley a large advantage after the sacrifice, he followed with some highly questionable moves, especially 34…g5?, a hasty move that badly weakened his kingside. This allowed Robson to fully reverse the evaluation and cash in with his powerful a-pawn, looking at a completely winning endgame by the time control. Wesley resigned on the 42nd move.

While happy to have won, Robson expressed guilt over beating his former teammate. “Obviously, [So] is the best player I’ve ever beaten in a tournament, so it’s a great feeling. I feel bad that I kind of ruined his chances for the tournament, but overall I can’t complain with a win … I still think Hikaru is the clear favorite. He already has the lead, and he’s already played Wesley and Gata. I’m still expecting him to win a lot more games.”

Robson takes White against Nakamura in Round 10 on Saturday, April 11.

GM Ray Robson vs. GM Wesley So Annotations by GM Josh Friedel

GM Alex Onischuk fought through a long rook endgame to claim victory over defending U.S. Champion GM Gata Kamsky. // Austin Fuller photo

In one of the finer technical games of the 2015 U.S. Championship so far, GM Alexander Onischuk nursed a small advantage and converted a long rook endgame against the reigning champion GM Gata Kamsky, otherwise known as a notoriously resilient defender. After five draws, the win puts Onischuk at 3.5/6 and a point off the lead in third place.

Afterwards, he offered a half-joke about his goal for the rest of the tournament:

“Just keep my plus score! Of course, I have a tough finish: I have three Blacks against top players -- Nakamura, So and Shankland -- but this game gave me some confidence, for sure. It was an important win.”

Young stars GM Kayden Troff and GM Sam Sevian pulled no punches in their Round 6 match-up -- with Sevian coming out on top after Troff failed to follow up on a promising exchange sacrifice. Also interesting was GM Conrad Holt vs. GM Varuzhan Akobian, where Akobian’s sacrifice earned him solid attacking chances -- but he blundered a full piece in the second time control and resigned just a few moves later.

GM Alexander Onischuk vs. GM Gata Kamsky Annotations by GM Josh Friedel

WGM Katerina Nemcova has been all smiles since taking the lead in Round 2. Tuesday's win over Jennifer Yu was her second checkmate of the event. // Austin Fuller photo

In the women’s event, Jennifer Yu caught leader Nemcova by surprise in the English opening, afterward admitting to commentators that she “did not prepare 9.Nxe5 at all.” Despite this, Nemcova kept calm and played well through a complex endgame where she received full compensation for a sacrificed pawn. Yu also played well until the very tempting 25.e6, bait that lead to Nemcova’s nice sequence of 25…Bd7! and 26…Kc8! The combo gave up her bishop with check in order to exploit pressure along the e-file, in a surprising turn of events that gave Nemcova a decisive advantage in a double-rook endgame. The game was shockingly ended in checkmate -- her second of the tournament -- as Nemcova ensnared Yu’s king in the middle of the board.

“I feel very well, I’m really happy the way I’m playing the opening, the preparation works,” Nemcova said. “I get everything I want in the game, and then opponents give me a piece or they blunder.”

WFM Jennifer Yu vs. WGM Katerina Nemcova Annotations by GM Josh Friedel

Reigning Women's Champion GM Irina Krush couldn't find a way past WGM Anna Sharevich on Tuesday and slipped from the leader's pace. // Austin Fuller photo

Nemcova’s fortunes grew as GM Irina Krush could not find a way to finish off WGM Anna Sharevich, despite holding a significant edge for most of the game. In the Fianchetto Variation of the Benoni, Krush played the theoretical exchange sacrifice 12…Rxf4, taking the game into dynamic territory. Krush then slowly outplayed Sharevich, who could do nothing with her extra rook as Krush’s pawns, supported by her minor pieces, simply charged down the queenside.

“I was just trying to find the best moves I could.” said Sharevich. “From the opening, I think she knew the line better than I did.”

In a desperate attempt for counterplay, Sharevich advanced her e-pawn with 34.e5, hoping to drum up an attack against Krush’s king. Krush then faltered with 36…Rd8 and 37…fxe6, suddenly activating all of White’s forces and giving Sharevich the chance to start creating threats. By the 40th move time control, both sides had a pawn on the seventh rank and the position had become unclear.

Sharevich could have forced a draw with 42.Rd8 but instead played 42.Rxg6+, which also seemed to force a perpetual.

After Sharevich’s 42. Rxg6+, Krush could have blocked with the beautiful 42…Bg7!!, halting White’s attack and allowing her b-pawn to queen. Instead, Krush recaptured with 42…hxg6 in haste, a decision that allowed perpetual check and Sharevich to escape with the draw.

“After I took Rxg6, [Krush] took back right away,” Sharevich said. “She could have thought for, I don’t know, 20 minutes and calculate everything.”

The missed opportunity leaves Krush at 4/6 and now a full point behind Nemcova. Also at 4/6 is IM Rusudan Goletiani, who topped WCM Apurva Virkud on Tuesday. WGM Tatev Abrahamyan has shaken off a slow start with another win, on Tuesday against WGM Sabina Foisor, pushing her to 3.5/6. IM Nazi Paikidze also stands at 3.5/6 after her Round 6 draw with WIM Annie Wang.

WGM Anna Sharevich vs. GM Irina Krush Annotations by GM Josh Friedel

Round 7 continues Wednesday at 1:00 p.m. CDT. Tune in to www.uschesschamps.com/live to follow the live commentary presented by GM Yasser Seirawan, WGM Jennifer Shahade, and GM Maurice Ashley.