Chess Cloud Database Query Interface

[noobpwnftw]

The back propagation of scores consider many factors: it does not prefer draws, a small penalty is given for non-progression, the number of counter-moves and their score contribution to the final weighted average score. White and black are not strictly treated equally to prevent those effects to cascade. It will very likely to produce slightly different move evaluations than any engine would do, since some "tweaks" to the score are invented by myself while some of those calculations are simply too expensive to perform for an engine.

Playing for some borderline advantage that may not convert and may backfire is just as "bad" as playing safe, however once a line is learned/discovered by CDB it will adjust scores accordingly.

[Ovyron]

White and black are not strictly treated equally to prevent those effects to cascade.

Now I'm strongly against this. If there's some English variation that reaches a position exactly like a Reversed Sicilian (colors are swapped), then not only the analysis of both should be exactly the same, you can just produce a single analysis and link it so it's valid for both colors playing the positions (so any node that you analyze on the Sicilian makes it to that variation of the English with colors reversed, and vice versa.)

The Houdini chess engine does something like this, but instead of using colors it checks who has the advantage, so white and black are not strictly treated equally, but in positions where black has the advantage, white is treated like black and black is treated like white. Perhaps this would be an improvement.

[noobpwnftw]

Flipping colors of the board is not exactly the same as "reaching certain position with which side to move", they are different concepts.
Positive scores and negative scores have different weighted averaging windows, it may be similar to what some engines did. Internally, CDB counts the shortest line to reach a position from start position, this is a property of the position itself, in order to measure "progression" of certain lines and "degrade" its scores on their parent, which may solve some fortress issues.

So if you reach a certain position from different lines, CDB will provide the exactly same results, on the other hand, if CDB discovers a shorter line that leads to the same position, then this property is updated and all subsequent scores will be recalculated.

[Ovyron]

I see, that's very cool and I think ChessDBCN is the only database with those features (I should have checked, 1.e4 e5 and 1.e3 e5 2.e4 show the same analysis flipped and are scored the same so white and black are treated equally in such cases). I still don't like those highly scored variations that lead to a 0 position if you play the best moves, but I can't think of a way to avoid that.

[Master Om]

The back propagation of scores consider many factors: it does not prefer draws, a small penalty is given for non-progression, the number of counter-moves and their score contribution to the final weighted average score. White and black are not strictly treated equally to prevent those effects to cascade. It will very likely to produce slightly different move evaluations than any engine would do, since some "tweaks" to the score are invented by myself while some of those calculations are simply too expensive to perform for an engine.

Playing for some borderline advantage that may not convert and may backfire is just as "bad" as playing safe, however once a line is learned/discovered by CDB it will adjust scores accordingly.

I still dont understand how a move scores at top if black can make draw by repeating the move order again and again ?

[EroSennin]

I find the database mostly useless. So many lines from human games are missing. And often at the top is some weird move that's nothing special or plain wrong.

[Ovyron]

But you can insert the missing lines, and feed it the lines that you have it best so it becomes more correct, and perhaps it'll show at the top some move you haven't considered in analysis.

[EroSennin]

But you can insert the missing lines, and feed it the lines that you have it best so it becomes more correct, and perhaps it'll show at the top some move you haven't considered in analysis.

There are just too many lines missing. I get more benefit by using online chessbase. I see the percentages humans have actually scored in games with engine evals, though blitz and rapid games nowadays are slightly distorting the results.

[Master Om]

I find the database mostly useless. So many lines from human games are missing. And often at the top is some weird move that's nothing special or plain wrong.

yes many lines are missing.