St. Louis Rapid & Blitz, Day 5 (Final Day): Carlsen & So Tie for First
It was a remarkable final day, and when one considers what a great clutch player Magnus Carlsen is, that he entered the last day with a half point lead over Wesley So, and that he defeated So in their individual game today, it's not surprising that he finished in first. What is surprising is that So managed to make up the point and a half in the remaining eight games to share first place. (There was no tiebreak or playoff in the event.)
In the first round of the day, Hikaru Nakamura, who finished in a very strong third place, defeated Carlsen in brutal fashion...well, mostly brutal fashion. Nakamura blundered on move 12, but Carlsen didn't notice it, and then things quickly went downhill. So drew his game with Xiong, bringing him into a tie with Carlsen.
In round 2 So went for a well-known anti-Berlin drawing line - one that occurred at least twice more over the course of the day's action - to take a round off against Nakamura, while Carlsen was given a colossal gift against Ian Nepomniachtchi. Nepo was completely winning and enjoyed a huge time advantage, but played a series of dreadful moves to go from won to lost. Somehow, to his credit, he rebounded and managed to save the game, so the first-place tie remained.
In round 3 Carlsen outplayed So (though not altogether cleanly), won, and took a full-point lead. Normally, that would be that, but after his unambitious play pretty much throughout the blitz, So finally started playing like a man who wanted to win the tournament, and he went +4 in the remaining six rounds.
In round 4, Carlsen demonstrated an ingenious idea with Black against Levon Aronian in a Giuoco that led to a short but brilliant draw. So, meanwhile, won speedily against Leinier Dominguez to close the gap to half a point, regaining the status quo ante from the start of the day.
The relative standings were the same after round 5: Carlsen drew with Black against Dominguez and So drew with Black against Alireza Firouzja.
Round 6 was a bright moment for the world champion, as another nice opening idea led to a nice victory over Pentala Harikrishna, while So was unable to achieve anything with White against Alexander Grischuk. Carlsen led by a point again, with just three rounds remaining. Normally, that would be the end of the story, but not this time.
In round 7, Carlsen could only draw with White against Firouzja, while So won speedily with Black against Nepo's 1.e4 e5 2.Nc3 Nf6 3.d4 exd4 4.Qxd4 Nc6 5.Qd3 - a contemporary twist on the Center Game. There's probably nothing terribly wrong with the line, whose most notably advocate prior to this game was Daniil Dubov, but it didn't work so well in this game. Back to a half-point deficit.
In round 8, So won again. Alexander Grischuk had a fine position with Black, but overestimated his attacking chances. More importantly, he missed a neat tactical trick - he had probably missed 25.Bd3 several moves earlier, and once it appeared on the board (er, on the screen) it was hopeless. Carlsen maintained his lead, smoothly defeating Jeffery Xiong on the black side of the 1.b3 opening. Carlsen quickly obtained the advantage, and when seeing games like this one wonders why anyone would bother with 1.b3. Of course, it's not really so simple, and Carlsen (and other super-GMs) have won such smooth games against mainstream openings that one might ask why anyone bothers with any opening against him.
Finally, round 9 on the day, round 27 overall. A win would seal clear first for Carlsen, but that plan was nipped in the bud when Grischuk used the same lame anti-Berlin line So used against Nakamura in round 2. That left the door open for So, if he could defeat Harikrishna with the black pieces - and as you already know, he did. Thanks to his 3-0 finish, he tied for first - a great result!
As for the blitz, Carlsen and Nakamura tied for first in that discipline over the last two days, scoring 12/18, with So scoring 11 points. Nakamura was especially strong today, scoring 6.5/9. Aronian and So both went 6/9 today, largely on the strength of his 4.5/5 start (only allowing the short, exciting draw with Carlsen noted above). I think Carlsen played better chess today than he did yesterday, but excepting the gift against Nepomniachtchi didn't get the sort of luck he did in yesterday's action, and finished with "only" 5.5 points today.
Here are the final standings (out of 36 points; remember that the rapid games were evaluated on 2-1-0 scoring):
1-2. Carlsen, So 24
3. Nakamura 21
4-5. Grischuk, Aronian 18.5
6. Nepomniachtchi 18
7-8. Harikrishna, Xiong 15.5
9-10. Dominguez, Firouzja 12.5
Tournament website here, a few games (with brief comments) here.