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The analysis tool can't count

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Avatar of llama47
llama47
Apr 20, 2021
0
#21

And when the majority of your users are under 1000 and under the age of 15 it's no wonder...

Avatar of Ziryab
Ziryab
Apr 29, 2021
0
#22
Ziryab wrote:

While this game, which features a potentially unsound gambit, but follows the great originator Gioachino Greco 100% netted a 99.6!

http://chessskill.blogspot.com/2020/01/near-perfect.html

Weird.

 

Close to the same game, but 99.7 this time: I used 29 seconds for twenty moves. Probably get reported. All Greco.

 

https://www.chess.com/analysis/game/live/13480916501

 

Avatar of Elroch
Elroch
May 1, 2021
0
#23

That Greco guy got away with murder.

Avatar of Born2slaYer
Born2slaYer
May 1, 2021
0
#24

I agree with the post I have faced the same.

Avatar of Ziryab
Ziryab
May 6, 2021
0
#25

The math continues to mystify.



Avatar of Elroch
Elroch
May 6, 2021
0
#26

Higher "Best move %", I bet.

Avatar of llama47
llama47
May 6, 2021
0
#27

One I posted awhile ago.

-

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Avatar of Elroch
Elroch
May 7, 2021
0
#28

That is an impressive number of blunders for over 90% "accuracy". Or do I mean an impressive "accuracy" for 6 blunders?

Avatar of jas0501
jas0501
May 7, 2021
0
#29

FYI, comment #1 game analyzed depth=26, in Beta with CEE CAPS2 values:

Avatar of llama47
llama47
May 15, 2021
0
#30

So today I'm looking at some analysis.

My opponent's moves that send the game from 0.00 to 2.86 in my favor isn't a blunder (it's a mistake).

Same opponent, different game, a move of his that changes it from -13.6 in my favor to mate in 4 is classed as a blunder.

Really silly.

In reality the first move I mention is a game losing blunder, and the 2nd should be completely ignored... every move loses so it doesn't matter (I queened in an endgame).

Avatar of llama47
llama47
May 15, 2021
0
#31
Elroch wrote:

That is an impressive number of blunders for over 90% "accuracy". Or do I mean an impressive "accuracy" for 6 blunders?

Yeah, I titled my topic "I don't need your pity chess.com"

Giving me >90% on a game that I should have lost 6 times (if we assume the blunders are actual blunders).

Avatar of Chushoudelu
CM Chushoudelu
May 15, 2021
0
#32

I believe that forced moves aren't listed, as they don't really count it as a "move" if you can't do anything else

Avatar of Ziryab
Ziryab
May 15, 2021
0
#33
TonyL103 wrote:

I believe that forced moves aren't listed, as they don't really count it as a "move" if you can't do anything else


Earlier in this thread it was noted that I made more moves than my opponent. The difference was the number of moves with no choice.

Avatar of Anonymous_Dragon
Anonymous_Dragon
May 15, 2021
0
#34
llama47 wrote:

So today I'm looking at some analysis.

My opponent's moves that send the game from 0.00 to 2.86 in my favor isn't a blunder (it's a mistake).

Same opponent, different game, a move of his that changes it from -13.6 in my favor to mate in 4 is classed as a blunder.

Really silly.

In reality the first move I mention is a game losing blunder, and the 2nd should be completely ignored... every move loses so it doesn't matter (I queened in an endgame).

+1

Avatar of Elroch
Elroch
May 16, 2021
0
#35

I agree.

Avatar of Elroch
Elroch
May 25, 2021
0
#36

Another interesting example of the meaningless of the accuracy percentage. Here is a (probably faultless) "64% accuracy" win in 11 moves. No inaccuracies, no mistakes, no blunders, 0.07 CP error, but "9.1% best move". Even with the creative arithmetic mentioned earlier, this last stat was a bit unlucky as 2 or 3 of the 4 non-book moves appear to be top computer choices now (must have been just 1 when it did the analysis).

 

Avatar of Ziryab
Ziryab
May 25, 2021
0
#37

And at the other end, I was docked a mere 0.6 for missing a win in a game lasting 18 moves. How do I know it was 0.6? I’ve played the entire game before without missing the quicker win (see post #3).

Avatar of Elroch
Elroch
May 27, 2021
0
#38

Today the analysis tool has got round any problems with counting by saying its "not a number".

Avatar of Elroch
Elroch
Jun 13, 2021
0
#39

It seems to be extremely rare that the analysis tool awards me a !! "brilliant". So it was nice to get one here.

Amusingly the move is a capture of a loose piece. But I do see what it means - to really justify it, I had to infer that the a-pawn was not too dangerous (it wasn't).

Avatar of Optimissed
Optimissed
Jun 13, 2021
0
#40
Elroch wrote:

There are no provided definitions for the various statistics but one would expect the best move percentage to have a close relationship to how many best moves were played. Does it? Not as you might expect.

https://www.chess.com/live#g=12061959371

In this game white played 11 moves, the first 5 of which were the mainline Ruy Lopez. Of the remaining 6 moves, the first is rated by the tool as "Excellent" and the other 5 as "Best move".  Yet it also says that the best move percentage was 45.4%.

This percentage clearly corresponds to 5/11 so I infer it includes the book moves in the denominator (11) but not the numerator (5). Unfortunately for this justification, some of the moves in this opening line happen to be clear engine top choices. This is most clear in the case of move 5, where there is only one move that does not lose, 5. Bb3, retreating the attacked bishop.

So, what you appear to have is a percentage that counts all opening theory as inferior moves. Games where you follow theory longer have lower best move percentages as a consequence.

I suspect this was the opposite of what was intended. It seems plausible that the intention was to count all opening theory as "best moves", while instead they all get counted as "non-best".

 

Yes, (just noticed this thread) the accuracy score provided by the analysis tool is usually mathematically impossible.