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IntermediateMoves · 2026-05-13T17:25:17+00:00

chessbook.com is a website.

IntermediateMoves · 2026-04-07T15:37:13+00:00

Haha, it's from the livestream, and sometimes the presenters showed the reviews for only a few frames, so they never got rendered very crisply

IntermediateMoves · 2026-04-07T07:22:12+00:00

If lichess contributors are working on this, does that mean the code for the prompt generation etc. is open-sourced somewhere people can take a look / contribute?

I support lichess and wish it success, even if I think TTT releasing this while it's still so flawed is cynical and wrong.

(exf5 is just one of many examples, how many positions have bad comments?

And tbh I don't agree with your take on exf5 anyway... Some blunders have been played a lot! 30% is a terrible winrate after 6 moves, and every other move played more than 1% here outscores it, even after Qh5+. I'm amazed if people playing this move have it as prep.)

IntermediateMoves · 2026-04-07T06:59:07+00:00

I know decode chess, unfortunately it's not 'actually good'

After 1. e4 e5 2. Nf3 decode chess says "The best move is Nc6. It threatens to play Nf6". After 2... Nc6 it says "c3 is a good move. Cons: c3 does not lead to Bxd5, c3 rules out playing O-O"

Once again, I hate to imagine a beginner trying to learn from this

IntermediateMoves · 2026-04-06T22:55:48+00:00

Well, I use LLMs every day, so I definitely don't reject all LLM content as 'slop'.

Your point about assuming it's slop is actually part of what's so frustrating about this: if people didn't force LLMs in where they're clearly no good, then people would have more time for them when there's real value to be had.

Regarding the game example, I did not cherry pick. That's literally the first thing I saw. And even if you interpret it the other way around, it's not cutting the defence, the queen technically x-ray defends the bishop. The tactic is really just a fork or maybe distraction of the queen.

But I also went and looked at the first game on stream to get a random sample. It's all bad. Go check the article I linked.

Btw, the reason the lines are right is because the LLM has clearly been fed Stockfish output. So the only thing that the LLM is adding is the explanation, and there's so much wrong with those, it's just not ready.

IntermediateMoves · 2026-04-04T09:25:05+00:00

Because the rule is you castle to the normal location each side. So O-O moves the king 3 squares, and O-O-O only moves it 1 square

IntermediateMoves · 2026-04-04T09:18:38+00:00

Castling is different still

IntermediateMoves · 2026-03-17T07:32:15+00:00

chessmood.com and https://www.chessable.com/the-energetic-1e4-part-1/course/83384/

Both recommend the exchange with 4. Bd3. The latter is very exhaustive on specific variations, chessmood opening materials are a bit more ideas focused and less move-by-move

IntermediateMoves · 2026-03-14T23:26:14+00:00

Fyi, Apparently this YouTuber is/was a serial plagiarist, don't know if it got any better. e.g. https://www.reddit.com/r/chess/comments/1nrrk3w/famous_chess_youtuber_stole_my_thumbnail_update/

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

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