It has been a few days, and any delays on my part cannot be chalked up to NCAA basketball (who cares? Notre Dame isn't playing). I could try to blame my getting my first vaccination (no side effects, thankfully, though I'm hoping it will improve my playing strength by a couple of hundred points), but that would be a joke. Anyway, delays or not, you'll at least benefit by receiving a bunch of annotated games. (Mostly light annotations [insert photon joke here], but there should be something instructive or at least entertaining in the mix.)
To catch up where we left off, we had this situation after day 1 of the quarterfinals: Magnus Carlsen and Wesley So had won their first mini-matches with Levon Aronian and Alireza Firouzja, respectively, while the Ian Nepomniachtchi vs. Hikaru Nakamura and Anish Giri vs. Maxime Vachier-Lagrave mini-matches were drawn. Unfortunately, there was little drama on day two, and after two games all four contests were at match point. Carlsen won game 1 and drew game 2 with Aronian, and needed just one more draw to clinch the match. So did the same but in reverse, winning game 2 after a draw in game 1. Nepomniachtchi won both games 1 and 2 against Nakamura, while Giri won game 2 after an initial drew against MVL.
Three of the matches finished after the next game - Carlsen drew, So won, and Nepo drew, and all three thereby advanced. Giri's draw in the third game gave Vachier-Lagrave the chance to force a tiebreaker, if the latter could win with Black in game 4, but as it happened he lost in a Modern in just 20 moves.
On to the semis, with the pairings Carlsen-Nepomniachtchi and So-Giri, with the favorites - and ultimately, match losers - listed first. Nothing terrible happened in the first two games on day 1: two clean draws in the first match, and a win for So with Black in game 1 (thanks to a Giri blunder). So made what I take to be a mistake in game 2 (though some think this strategy is okay), wasting the white pieces by allowing Giri to make the same draw that occurred three months earlier in the game So-Nepomniachtchi. Giri built off of this psychological respite with a win in the third game, and then took advantage of So's blunders in the last game to take the first day's mini-match 2.5-1.5. As for Carlsen, game 3 was a disaster. A good opening and early middlegame gave him a winning advantage with White, but a fairly simple oversight prevented him from exploiting that advantage. He was still okay after that, but a later, mistaken exchange sacrifice left him with a lost position, and Nepomniachtchi cashed in to take the lead. Carlsen tried hard in game 4, but Nepo held and won the day, 2.5-1.5.
On day two, So was unable to dent Giri. He had a chance in the first game, but failed to convert, and Giri also had a chance for a significant advantage in game 2. But both games were drawn, as was game 3, and So was forced to play for a win with Black in game 4 to force a tiebreaker. He achieved a good position with the French, and after Giri's poor 26th move So was clearly better. Unfortunately, his reply was an outright blunder, and after Giri's 27th move So resigned, losing the game, mini-match, and the overall match.
Carlsen's comeback went better - though not at first. Game 1 was drawn, and then he lost game 2, overpressing once again. Now all Nepo needed was a draw to end the match, and in game 3 he had plenty of opportunities to achieve that aim. Every time he came close, however, he'd make a mistake, and after one error too many Carlsen managed to win. Game 4 was a blowout: Nepo was crushed out of the opening, and Carlsen sailed to a second straight win and victory in the second mini-match, tying the overall match 1-1 and forcing a blitz tiebreaker.
Nepomniachtchi had White in the first game, which went for a very long time, though without managing to be of much interest. Carlsen enjoyed a nominal endgame edge, and for simplicity's sake Nepo bailed out into the endgame R vs. R+N. While it's not impossible to lose the ending (we all remember Judit Polgar's loss to Garry Kasparov, right?) it's much easier to hold than R vs. R+B, and the weaker side generally holds it without much trouble. As one would expect from a near-2800 player, Nepo was holding it comfortably, and after 45 moves of mild suffering Carlsen blundered his rook (presumably a mouse-slip or a pre-move error). Now it was the World Champion's turn to hold a semi-trivial inferior ending (rook vs. knight), and after 36 or so more moves they finally called it a game: draw.
After those misadventures, it was Carlsen's shot with the white pieces. If the game finished in a draw, they'd go to Armageddon, but as Carlsen obtained the advantage and "his" kind of position, it looked like he'd win and advance to the finals. Surprisingly, his technique was a bit shaky, and when he once again overpressed in what had become an equal ending he went on to lose.
So that's where things stand: we've got a Giri vs. Nepomniachtchi final. Here are all the games from the semi-final matches, with at least cursory comments to most of the games.