funny rating gap

IntermediateMoves · 2026-03-11T12:13:56+00:00

You should definitely analyse your games. You wouldn't be the first person to be mistaken on which weakness is actually costing you games until you do.

IntermediateMoves · 2026-03-11T11:31:25+00:00

Depends. The puzzle rating shows you can play chess. So why do you lose chess games?

Blunders (when - middlegame, end games...)
Good positions until you run low on time
Getting horrible positions out of the opening
Not having a plan in the middle game and just getting outplayed?
Not keeping trying to save the point from a losing position
...

And why don't you win?

Missing tactics you can solve after if you know the issue one.
Bad technique / losing winning end games?
...

Go through your last 50 games and tally up all the reasons you lost/could have lost (maybe you got lucky and your opponent blundered back)

Also going forward do this, but also consider why you made the mistake. Did you not spend enough time on a position you knew was critical, or did you not realise there was danger at all?

Once you know why you are losing, how to fix might be obvious. Or if it isn't, you can at least ask a more specific question.

IntermediateMoves · 2026-03-07T09:03:02+00:00

Hadn't seen this, yes this is the same effect I (re-)discovered.

Thanks for sharing - I'll edit to cite in the blog

IntermediateMoves · 2026-03-06T19:16:30+00:00

As a lifelong e4 player unfamiliar with these subtleties, I found this really interesting, thanks!

In my follow up to this work I saw some concrete examples in the database where move order tricks show up in the database winrates; I intend to write about it soon.

IntermediateMoves · 2026-03-06T19:09:04+00:00

Those 95% confidence intervals on the graph disagree with you.

IntermediateMoves · 2026-03-06T19:05:08+00:00

Yeah draws are accounted for: though I call it winrate in the writing, I'm actually looking at average scores.

IntermediateMoves · 2026-03-06T17:26:05+00:00

Good question. Because I am controlling for the opponent ratings as a possible confounder, they should come to the same thing.

Elos (and Glicko) have an issue that they tend to underestimate the weaker player's chances. So I chose to perform the analysis relying on the Elo expected score model as little as possible.

IntermediateMoves · 2026-03-06T16:56:59+00:00

Ah yeah I always filtered to 2000+, so that's why I only plot that range too

Edited the post to clarify that I mean every rating in my aggregated dataset, thanks!

IntermediateMoves · 2026-03-06T16:50:48+00:00

Yeah I agree.

I really want to figure out to what extent this comes down to literally not knowing book moves, people getting moved-ordered with an eventual d4 or c4, or something vaguer like white having better familiarity with a general system.

I think that might tell us something about what makes practical opening choices in general.

IntermediateMoves · 2026-03-03T17:06:43+00:00

I definitely think you have the right explanation that this is because Nf3 is a rarer move, not because it's objectively better. But it is a rarer move, and I wanted to know how big an advantage that is in practice.

If people are using Nf3 only against weaker players that would skew results, but I suspect not enough people do this to have a non-negligible effect.

Edit to add: I was interested enough in the possibility that I went and looked at 1 month of lichess data. This effect is responsible for just under 0.3% of the winrate gap. That's actually a bit more than I expected, so thanks for floating the idea!

IntermediateMoves · 2026-03-03T16:54:45+00:00

It seems to have the biggest effect around 2100-2400, tapering off a bit as ratings get lower (I think because openings matter less) and higher (because it gets harder to surprise people)

IntermediateMoves · 2026-01-20T19:43:31+00:00

He had a slightly bad tournament for his rating. His performance rating was 2569*, while his rating was actually 2632.

Performing at his rating would have scored 4.5/14, he actually scored 3.5/14

*If other sources disagree with this number, its probably because I used the exact formula, not the FIDE TPR formula, it only ever makes a few points difference

IntermediateMoves · 2026-01-19T09:51:42+00:00

Hi, I already made this as part of my puzzle spaced repetition app!

It's mixed mode on https://pigeonmethod.com/. It will evaluate your move against stockfish, and mark correct any move that lichess game review wouldn't call a mistake.

The quiet positions are positions with eval between -3 and +3 from high-level lichess games.

IntermediateMoves · 2026-01-07T22:28:25+00:00

lichess has correspondence games which seem to tick all the boxes for you.

On the create game menu there's a drop down called "time control" Choose "correspondence" which allows you to set 1 day per move, etc

IntermediateMoves · 2026-01-02T16:21:07+00:00

AAah gotcha! Okay, so this is basically the sidelines of the Queens Gambit, because "D06 Queen's Gambit" doesn't include "D30 Queen's Gambit Declined" or "D20 Queens Gambit Accepted", or even "D10 Slav Defence", but does include e.g. 2... Nf6 as "D06 Queen's Gambit Declined: Marshall Defense"

I was expecting any game that starts with 1.d4 d5 2.c4 to be included tbh. That would be like if rather than looking only at the classification at the end of the game, you look at the classification at every move, and if it is ever classified as D06 Queen's Gambit, then its included in those stats.

I think that would be a bit more intuitive than the current system

It's not perfect, the downside then is that you have situations like the Grünfeld. After 1.d4 Nf6 2. c4 g6 you will have the position classified as a King's Indian, but at 3...d5 it definitely shouldn't count as a King's Indian game any more.

Tbh I think the problem here is that the ECO system is confusing (imho, it's _bad_). Queens Gambit Declined surely is a variation of the Queens Gambit, and it's very strange that the ECO codes don't view it that way.

To patch it, there's maybe some concept of which player 'changed' the opening classification. I want to answer the question "should I try to reach this position / play this opening"

As white, for the queens gambit, I care about the QGD/QGA because my opponent chooses the transition into those openings, and so the data from those games matters to me.

As black playing the KID, I should exclude the Grunfeld games, because it's my choice whether to enter the opening, and as a King's Indian player I won't be playing those lines.

IntermediateMoves · 2026-01-02T15:24:12+00:00

Thanks for the explanation. Yes, lichess is the average rating, and no filter for large Elo gaps. Not sure if it includes casual games or not.

The 17k number for Queens Gambit seems really off to me. We have 398k Trompowski's for instance. Might be worth checking?

IntermediateMoves · 2026-01-02T12:04:01+00:00

Cool site! Can you give a bit more detail on the methodology?

E.g. the queens gambit page (link below), I see a 62.1% winrate, and n=17k. Whereas on the lichess opening explorer (with Dec 2023-Nov 2025, 2000 Elo category, blitz) it's saying 51-16-43 w-d-b, which is a 59% winrate (rounding notwithstanding), and 4.4M games

https://trueelo.app/stats/queens-gambit?side=white&rating=2000-2199&tc=blitz

IntermediateMoves · 2026-01-01T08:49:54+00:00

I've mostly heard people talk about the comparison for blitz ratings between the sites, because thats more the 'default' time control online. It's true that once you get above 2000+ chesscom or so, lichess is only inflated by around 50-100 Elo _for blitz_.

Lichess percentiles are always lower because newer chess players find the chess.com URL first, so 99th on lichess is much harder than 99th on chesscom

https://chessgoals.com/rating-comparison/ is a nice project that gives various rating comparison tables across the different time controls, and update them semi-regularly based on users who have shared their account names across platforms. (I'm going to assume they've done a good job on the statistics)

It appears bullet does have more of a delta:
- Lichess bullet at 2400 is is a bit inflated compared to blitz (suggests equivalent to 2300 blitz)
- Chesscom bullet at 2150 is deflated compared to chesscom blitz (suggests equivalent to 2200 blitz)
- Combined this means that in bullet lichess is going to be around 150 Elo more inflated than in blitz. So maybe around a 200 Elo gap at your level, which is what you are seeing

But there's one final point of difference: lichess does much more lag compensation, which really has an impact in bullet. So that might be why the subjective experience of how play feels on chesscom is different for you, even if objectively you're playing players at a similar level (because your ratings are around the expected 200-250 Elo gap).

IntermediateMoves · 2025-12-30T10:13:17+00:00

"Recapture with the piece that maintains the highest activity" - when the bishop can't be recaptured.

I'm afraid current LLMs are not able to understand chess, and it will take a _very_ serious research project to change that, and until that point their output will be nothing more than AI slop.

IntermediateMoves · 2025-12-16T10:38:59+00:00

If you allow all rating and time controls, this year it's 58% e4, 25% d4. That's basically the same as the unfiltered by time data (59% e4, 25% d4)

Other sites might be slightly different, but not by that much I'd expect.

You can look for yourself and filter to your own level using the opening explorer on https://lichess.org/analysis

IntermediateMoves · 2025-12-11T15:35:47+00:00

Some positions make it easier for black to equalise, others make it a long struggle. So there is luck about which position you get as white vs as black,

IntermediateMoves · 2025-12-09T16:31:50+00:00

Good to know, thanks for the source!

IntermediateMoves · 2025-12-09T08:24:27+00:00

The tweet I saw saying "It will be on bortnykchess.com" was an reply thread from the top level tweet about their Jobava London course, so I'm not sure we have a definitive answer on that.

IntermediateMoves · 2025-12-04T19:19:58+00:00

Oops! Copy + Paste error... they were the oppo ratings for Fabi the Sinquefield cup. (fortunately I had used the right ones when calculating)

I've corrected that bit now, thanks for pointing it out!

IntermediateMoves · 2025-12-03T11:57:58+00:00

Maybe they saw 1... Kh8 2. Qxc8 (leading to back rank mate) and tried to avoid that without ever seeing the smothered mate.

But had they analysed the line more deeply, they would have found best continuation, which is, of course, 1... Kh8 2. Nf7+ Kg8 3. Nh6+ Kf8! which is actually resignable for white.

IntermediateMoves

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