Breaking the 3500 Barrier

Another seven-plus months, another 100 posts. Yesterday's post, Chess and Italian Design (October 2022), was no.3500 on this blog. That means it's time for a follow-up to Breaking the 3400 Barrier (February 2022). If you haven't seen the series before, the number 3400 also refers to a chess rating. We had to abandon humanity at Breaking the 2900 Barrier (April 2019), because according to the accepted rating agencies, no one has ever achieved that level.

Not too long after the 'Breaking 3400' post, I had another off-week engine post, Stockfish Breaks All the Barriers (April 2022). There I wrote,

I'll come back to this current post if I ever need to do a 'Breaking 3500' post.

So here we are. Believe it or not, a 3500 rating means we're approaching the current limit for engines. In the 'Breaking 3400' post I noted,

The ratings for [TCEC] 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, the CCRL.

Looking at that page CCRL Home (computerchess.org.uk/ccrl) again, I see there are two lists:-

• CCRL Blitz (1; Stockfish 15 64-bit 8CPU; 3745 rating)
• CCRL 40/15 (1; Stockfish 14 64-bit 4CPU; 3534)

The difference between a 37xx rating and a 35xx rating corresponds to the drop from TCEC S18 [37xx] to TCEC S19 [35xx]. I suppose that TCEC switched CCRL rating lists between S18 (finishing in July 2020) and S19 (October 2020). Or something like that.

That July-October 2020 time frame happened to coincide with the introduction of Stockfish NNUE, which saw a dramatic increase in the Fish's rating. If it wasn't rated 3500 before that period, it certainly was after. If I ever do a 'Breaking 3600' post, I now have two CCRL rating lists to consult, but I'll cross that bridge when I come to it. At the end of the 'Breaking 3400' post, I mentioned,

'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.

Reports last month proclaimed, e.g. Magnus Carlsen breaks 2900 barrier in Julius Baer Generation Cup win (chess24.com; Leon Watson). The article started,

Magnus Carlsen is the Julius Baer Generation Cup champion and the first player to break the 2900 Tour Rating after crushing the "Indian Iceman" Arjun Erigaisi in today’s final.

Given that Chess24.com is a defacto Magnus Carlsen fan club and that the record involved a '2900 Tour Rating' -- whatever that is -- the whole thing looks suspicious. TBD: Review for 'Breaking the 3600 Barrier'.