Today’s game is from the current US Junior Championship being held at the Chess Club and Scholastic Center of Saint Louis . After five rounds, we find a somewhat surprising leader in Utah native Kayden Troff, who was not really considered a contender due to his serious inactivity for the past year, but he’s a point ahead.
Going into the event, the clear favorite was 15-year-old Texan Ruifeng Li. He had the field’s highest rating, and he also had the best recent results. However, his tournament started out poorly, with a dreadful 27-move loss to Troff. We find him a full two points behind Troff with four games to go.
Today’s game is his high point so far in the event. It’s his third-round victory over newcomer Andrew Tang of Minnesota. After a rather nondescript opening, Li finds a target in Black’s white square bishop, causing Black to weaken his pawn structure, which White exploits with a direct assault on Black’s king.
2017 U.S. Junior Championship, St. Louis, Mo.
Ruifeng Li (2568) — Andrew Tang (2478)
1.b3 Even the young, with their endless energy and seemingly endless time for chess, have no interest in theory 1...d5 2.Bb2 c5 3.e3 Nc6 4.Nf3 Nf6 5.Bb5 Qb6 6.Be2!? Unusual, as the point of 5.Bb5 was to control e5. And with this retreat, White gives up that idea. 6...Bf5 Naturally Black wants to get the Bishop out before playing e6 but now it becomes a target for White 7.0–0 e6 8.Nh4 Bg6 9.d3 Be7 10.Nd2 Qc7 11.f4 d4 12.e4 Nd7 13.Qe1 Qd8 14.g3!? Daring Black to double his pawns but at the cost of weaken black squares and more open lines (the g-file) against his king. 14...Nf6 15.Qd1 Threatening f5 trapping the bishop 15...h6 More or less forced but now Black's structure gets badly damaged. 16.Nxg6 fxg6 17.Nc4 b5 18.Nd2 If 18.Ne5 Nxe5 19.fxe5 Nd7 20.Bh5 Nxe5 21.Bxg6+ Kd7 22.Qh5 Bd6 23.Bc1 White is slightly better 18...0–0 19.a4 a6 20.Bg4 Qd7 21.Bh3 Rae8 21...b4 22.e5 Nd5 23.Qg4 Kf7 24.Nc4 h5 25.Qf3 Kg8 26.Qe4 Kh7 27.Bg2 22.axb5 axb5 23.Nf3 Kh7 24.Qe2 Bd8 25.Bc1 Qb7 26.Bd2 26.g4 is the computer’s idea. Then after 26…Ba5 a crazy line is 27.g5 Nh5 28.f5! exf5 29.Nh4 Rf7 30.Nxg6 fxe4 31.dxe4 d3 32.Qxh5 Rxf1+ 33.Kxf1 Nd4 34.cxd3 Qf7+ 35.Kg2 should win 26...Bb6 27.Nh4 Gearing up for the forthcoming attack. 27...Bd8 28.e5 Nd5 If28...Nd7 29.Bg2 Bxh4 30.gxh4 Nb6 31.Be4 Qc8 32.h5 Ne7 33.hxg6+ wins a pawn 29.Nxg6! Kxg6 30.Qe4+ Kf7 31.f5 Kg8 31...b4 32.fxe6+ Kg8 33.Qxd5 Rxf1+ 34.Rxf1 32.fxe6 the whole point of the sacrifice is Rf7 followed by attacking on the 7th rank. 32...Nce7?! Last chance was 32...Ne3, though it gives back the piece, Black gets a chance to defend.; 32...Ne3 33.Rf7 Rxf7 34.exf7+ Qxf735.Qxc6 Rxe5 36.Qxb5 Bg5 37.Qc6 Nxc2 38.Rf1 Qe7 39.Ba5 Kh7 40.Qc7 Be3+ 41.Kh1 with just a small advantage for White. 33.Bxh6! Opening Black up. Now if 33...gxh6 then 34.Rf7 Rxf7 35.exf7+ Kxf7 36.Qh7+ Kf8 37.Qxh6+ Kg8 (37...Kf7 38.Be6#) 38.Be6# 33...Nf5 34.Bxf5 gxh6 What else if 34...Qe7 35.Bh7+ Kh8 36.Rf7 Rxf7 37.exf7 Qxf7 38.Bg6 Qg8 39.Bxe8 gxh6 40.Bxb5 Ne7 41.Rf1 Qg5 42.Bc4 35.Bg6 Rxf1+ 35...Rxe6 36.Rxf8+ Kxf8 37.Qf5+ Rf6 38.exf6 Nxf6 39.Qxc5+ is just winning, if 39...Kg7 40.Ra7 36.Rxf1 Rf8 36...Rxe6 37.Qg4 Rf6 38.Be4+ Kh8 39.exf6 Bxf6 40.Bxd5 Qxd5 41.Rxf6 37.Rf7! Rxf7 37...Qb6 38.Bh7+ Kh8 39.Rxf8+ Kg7 40.Rg8#; 37...Be7 38.Bh7+ Kh8 39.Qg6 38.Bxf7+ Kf8 38...Kg7 39.Qg6+ Kf8 40.Qg8+ Ke7 41.Qe8# 39.Qh7 Qc6 39...Ke7 40.Qh6 threatening 41.Qg5 mate wins; 39...Ne7 40.Qxh6# 40.Qxh6+ Ke7 41.Qg5+ This leads to mate after 41...Kf8 42.Qxd8+ Kg7 43.Qg8+ Kh6 44.Qg6#; 1–0Chris Chase can be reached at BostonGlobeChessNotes@gmail.com.