1.d4Nf62.c4e63.Nc3Bb44.Qc2O-O5.a3Bxc3+6.Qxc3d57.Nf3dxc48.Qxc4b69.Bg5Ba610.Qa4Qd711.Qc2c512.dxc5Rc813.Rd1...13.Bxf6was played by So, among many others.gxf614.Rd1Qe715.Qe4Qxc516.e3Bxf117.Kxf1Nc618.g3Ne519.Kg2Qc620.Qxc6Rxc621.Nxe5fxe522.Rd2with an equal position and an eventual draw in So – Nakamura, Bilbao, 2016.13....Qe714.Qa4!?...14.e4has been seen in the vast majority of games, including once by So last year:Bxf115.Kxf1h616.Bxf6Qxf617.e5Qe718.Qe4Nc619.cxb6axb620.g3b521.Nd4Nxd422.Rxd4Ra423.Rxa4bxa4with an eventual draw in So – Caruana, St. Louis, 2023.14....bxc5N14...Qxc5was tried in the one previous game in the database:15.Bxf6gxf616.e3Bxf117.Rxf1Nc618.Ke2Na519.Rc1Qf520.g4Qd521.Nd4Qe422.h3Rc5??(22...Qd5⩲)23.b4Rc4(23...Rxc124.Rxc1Nb725.Qd7+−)24.Qd7e525.f3Rxd426.Qc8+!Rd827.Qxd8+Rxd828.fxe4Nb329.Rc2a530.Rxf6and Black resigned in Torres Rosas – Ruiz, Charlotte, 2021.15.h4c4The alternative was:15...h6when16.Rh3was still playable! Likely the game just transposes after(16.g4!?was also very interesting.Bb7!(16...hxg5?!17.hxg5Nh718.Qf4⩲is White's path to an advantage.(18.Qe4Nf8is equal, as19.Qxa8??Nc6-+is a thematic trap in these variations.))17.Bg2∞)c4.(16...hxg5??17.hxg5and now the threat of Qa4-h4 necessitatesc4when White is better after18.gxf6Qxf619.g4±)16.Rh3!?...A logical idea considering Black's bishop's placement on the f1-a6 diagonal. But16.e3was also logical!h6(16...Qb7is more solid:17.Bxf6gxf618.Rd2Bb519.Qd1Nd7=)17.Be2hxg5leads to chaos:(17...Bb718.Bxc4Bc619.Bb5⩲)18.hxg5Ne419.Rd4!f520.gxf6Nxf621.Rdh4Qc522.g4∞16....h617.Qc2!?...White's bishop remains invincible on the g5-square, but as Black completes development it's hard to not pity White's king and undeveloped light-squared bishop.17.Bd2was best:Ne418.g4is consistent expansion.Nc519.Qc2Nc620.g5h521.g6f622.Be3Nb323.Nd4Ncxd424.Bxd4Rd825.e3=17.Bxf6allows Black to equalize.Qxf618.Nd4Rd819.Rf3Qxh420.g3Qe421.Re3Qb722.Rd2Rc823.Qb4Nc6⩱17....Nbd718.Nd4?!...18.g4!was White's best shot.Bb719.Bxf6Nxf620.g5Ng421.Rg3h522.g6f523.Ng5Qc524.e4!is the sort of energy that White needs to keep his pieces active. Play could continue, e.g.Bxe425.Nxe4fxe426.Bh3Rf827.Bxg4hxg428.Re3Rab8⩱with lots of chances for compensation from Black's weak pawns.18....Bb719.Bd2a520.f3Qc521.Be3c322.Qxc3Qxc3+!?22...Qf8!23.Qd3(23.Qb3Rab824.Qa2a425.Kf2Bd526.Qb1Bc427.Rc1Nd5!28.Bd2Qd6∓)Ba624.Qb1Rab8∓23.bxc3Rxc324.Bc1...So's choice to trade queens was a bit conservative. Black's position is still for choice, but the queen trade definitely lowers the risk.24....Ba625.e4Bxf126.Kxf1Rac827.Bb2R3c528.g4Nb628...Rb8!?29.Rh2Ne530.Ba1Nc4was a bit more testing, going after the a-pawn.31.Re2Nxa332.Ra2Nc433.Ke2Ne5Apparently, White has compensation here after34.Rc2Rxc2+35.Nxc2Nc636.Rd6Nb4but this is far from obvious.29.Rh2Nc430.Ke1Nxb230...Nd7!?is a sharp idea, aiming to re-route to the e5-square and create complications. White can play31.Nxe6whenNde532.Bxe5Nxe533.Nxc5Nxf3+34.Ke2Nxh235.Rd5Nxg436.e5Re837.Nd3a4is probably not enough38.Ra5f639.Rxa4Nxe540.Re4Kf7peters out to a draw.31.Rxb2Rc3So continues to grind the modest advantage, rather than play for something more ambitious.32.a4Ra333.Rb6Rd833...Rcc3!?34.Rb5Rxa435.g5Nh5when White must play36.g6fxg637.Nxe6forcingRc8when White is in time with38.Rd7Ra239.Rbb7=34.Rb5g634...Nxg4!?35.fxg4Rxa436.Ne2Rxd1+37.Kxd1Rxe438.Rxa5g6is, oddly enough, the engine's choice. I suppose Black is not losing this by any means. But "make sure you can't lose" didn't seem to be Black's goal from the previous position.35.Nb3Rc836.Ke2Rc437.Rd8+Kg738.g5Nxe4!39.gxh6+Kxh640.fxe4Rxe4+41.Kf2Rexa442.Nd4Ra2+43.Kg3R4a3+?43...R2a3+!44.Nf3Rb4=(44...Kg745.Rd7Rb4was just as good.)44.Nf3Re2?With 43. ... R2a3+ instead of 43. ... R4a3+, Black would have had ... Ra4-b4. Without this resource, Black's defensive task is much more difficult.44...Kg7was Black's best chance.45.Rd7Kf6!46.Rbb7e5when now47.Rxf7+Ke6at least forces White to find48.Rg7!Re2(48...Kf6?49.Rbe7+−)49.Rxg6+Kd550.Rd7+Kc451.Rg4+Kc552.Rg5Kc6when Black is still fighting! Only53.Rh7keeps an objective advantage.45.Rb7...It's over. If Black pushes the f-pawn, Rh8+ is mate. Otherwise, White grabs the f-pawn, inches toward mate, and defends the f3-knight to boot.45....Re546.Rxf7g547.h5Kxh548.Rf6When Black resigned, as 48. ... Rxf3+ was the only move that avoided mate-in-one, but the three disconnected pawns would not compensate for the rook here.1-0