Breaking the 3400 Barrier

Yesterday's Flickr post, 1.Nf3 in Zalaegerszeg (February 2022), was post no.3399 on this blog, making this off-week engine post the perfect spot for the follow-up to Breaking the 3300 Barrier (August 2021), my most recent periodic look at century milestones in chess ratings. In that '3300 Barrier' post I calculated that the interval between 'barrier' posts was seven months, so we're slightly ahead of schedule.

My first idea for this current post was to look at the ratings of engines from important TCEC/CCC events, but I encountered an anomaly. For TCEC S21, last seen on this blog in TCEC Stockfish Wins S21; CCC Romance Continues (August 2021), the top three engines in the semifinal event were rated:-

S21 - Division P
1 Stockfish 2021061923 • 3632
2 LCZero 0.28.0-rc1_69146 • 3614
3 KomodoDragon 2747.00 • 3582

Those ratings were higher than for the top three in S20, which were higher than S19. For S18, last seen in Stockfish Wins TCEC S18; Leela Wins CCC14 (July 2020), the top three were:-

S18 - Division P
1 Stockfish 202005232210 • 3796
2 LCZero v0.25.1-sv-t60-3010 • 3809
3 AllieStein v0.7_dev-net_14.3 • 3761

In other words, the ratings for S18 were considerably higher than for S19 and subsequent TCEC seasons. Not knowing how to resolve this problem, I turned to another source for engine ratings, CCRL Home (computerchess.org.uk/ccrl). The top three engines there are currently:-

1 Stockfish 14 64-bit 4CPU • 3541
2 Dragon by Komodo 2.6 64-bit 4CPU • 3527
3 Fat Fritz 2 (in SF) 64-bit 4CPU • 3517

And when did engine ratings break 3400? Older CCRL results are available in Archive.org. The oldest results, from March 2019, are captured in the following image.

Source: Wayback Machine

The highest rating is 3463 for Stockfish, with the next two engines just under 3400. That's the closest I got to answering my question.

As for the human contingent, Magnus Carlsen targets all-time rating record of 2900 (theguardian.com; Leonard Barden; January 2022). When I come back in 6-7 months for 'Breaking the 3500 Barrier', I'll check the World Champion's progress.