As mentioned a couple of posts ago, what counts most in the 16-person preliminary stage of the Aimchess Rapid is that one finishes in the top eight. Scores are not carried over to the final, so the only significance of how one finishes, as long as one is in the top eight, is one’s seeding. If Magnus Carlsen finishes with the best score, for example, one would like to avoid being the eighth seed and having to face him in the quarterfinals; better to face him in a later match, if only in the interest of winning more prize money before getting eliminated. (Not that the loss is guaranteed, but we’re playing the percentages here.)
The prelims place a premium on winning with its 3-1-0 scoring system. It’s better to draw than to lose, but (within reason) to go for relatively volatile positions in which the risk of a loss may increase, but the opportunities for a win are increased as well. Given the short time control (15’+10”) and the fairly wide range of ratings in the event, it’s not clear that the 3-1-0 system is a necessary expedient for significant bloodletting, and the six draws in eight games in round 4 showed that it’s not a sufficient condition for producing decisive results, either. But, to invoke a contemporary cliche my mother hated (but not for that reason!), it is what it is.
After the day’s action, Nodirbek Abdusattorov leads with 3.5/4 - or rather, 10/12, winning his first three games before finishing with a draw. That has him three points ahead of five players (in tiebreak order): Shakhriyar Mamedyarov, Magnus Carlsen, Jan-Krzysztof Duda, Vincent Keymer, and Richard Rapport. Behind them Dommaraju Gukesh is in 7th with an even 6/12, and Santosh Vidit is in eighth with 5 points, by tiebreaks ahead of his countrymen Arjun Erigaisi and Mittal Aditya.
The main story of the day, at least for me, is Mamedyarov. In the first round, he was surprised in the opening against Carlsen and found himself in a lost position. (Several times.) Yet he kept fighting, and in the end it was Carlsen who cracked and lost. It wasn’t a great game, just a great result against a great player. For the great game, we move ahead to round 3, when Mamedyarov won a spectacular attacking game against Anish Giri. First he sacrificed a pawn, then the exchange, then two pieces and finally even the queen. It wouldn’t have been a difficult game to play at a slower game (and in one sense it would have been impossible, as a player of Giri’s caliber wouldn’t have lost in this way with more time on the clock), but it was impressive for 15’+10”. Have a look here, to see both that game and his win against Carlsen. (The notes are abbreviated, as I’m presenting the games in more detail for ChessLecture.)
Three more days of prelims will follow, and then the knockout stage.
The 3-1-0 scoring system was clearly introduced in response to some players - mainly Nakamura, So and Radjabov - going for lots of short theoretical draws in the preliminary phase of earlier events: the well-known Berlin sideline (mainline?), topical Grunfeld lines and maybe other short draws that had lots of predecessors.
It obviously cannot prevent all draws (only compulsory Armageddon would force decisive results in every game): no questions asked for any of the draws in round 4, two games went to bare kings, Harikrishna-Vidit took 153 moves.