Open h3h4ns563b opened 9 months ago
What depth did you go to? At depth 27 cloud analysis puts this position at +4.5 for me. Can you please check if you can still reproduce?
Yes, it still reproduces for me. It may have changed as now I see the +7.8 on white's turn 7 but not black's. However, I suppose it's possible that I misread before, so this time I got a screenshot.
Note the graph showing the spike to +7.5
Now, on the same move I've turned on the engine it drops to +4.5
I've been getting this quite a lot. It's not ideal because if I mistake this position to actually be +7.8 and then I explore variations and notice that the eval has dropped to +4.5, I assume that the variation is a mistake.
Tangential (non-cloud), but this PGN has spike from -3.6 on move 27 to -4.6 next move and progresses slowly to -6.2 on move 36. The general gist of the analysis from move 27 to 36 is still correct though and shows a fair advantage for black. EDIT: [Event "Casual Correspondence game"] [Site "https://lichess.org/tt4SomrZ"] [Date "2023.11.23"] [White "Anonymous"] [Black "lichess AI level 5"] [Result "1-0"] [WhiteElo "?"] [BlackElo "?"] [Variant "Standard"] [TimeControl "-"] [ECO "A00"] [Opening "Mieses Opening"] [Termination "Normal"] [Annotator "lichess.org"]
As far as I know the evaluations of the first few moves of an analyzed game are taken from "cloud" evaluations.
This can (as you can see) be very confusing when different engine versions can give different evaluations.
In this case the engine was most likely Stockfish 14.
Exact URL of where the bug happened
https://lichess.org/paste
Steps to reproduce the bug
Go to https://lichess.org/paste
Paste in the below game and request computer analysis.
e4 e6 2. d4 d6 3. Nf3 Be7 4. Bc4 Nd7 5. Nc3 e5 6. dxe5 dxe5 7. Qd5 1-0
What did you expect to happen?
All the various local engines and other sites I've tried evaluate the final position as ~+5
What happened instead?
The cloud engine evaluates it as +7.8
Operating system
Linux
Browser and version (or alternate access method)
Firefox 119
Additional information
This could be nothing of course, evaluations can differ depending on the engine used etc, but I've noticed a clear pattern now of the cloud engine giving inflated evaluations for positions.
Note that it could be related to the fact that the game is imported. I haven't been playing games on lichess for comparison. I've also only started importing games for analysis recently so I'm not sure if this is new.