Good question. Curious myself. Can't seem to find the answer here in the forum. Hopefully someone will reply with the answer...
Average Difference
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t shows how much your move varies from the computer moves/how much bad your move was during game on average.
in your case .84 and .72 means how much advantage you and your opponent lose per move on average during a game(lower average difference shows better quality of moves during a game)
it is also called average centipawn loss. from wikipedia-http://chess.wikia.com/wiki/Centipawn
The centipawn is the unit of measure used in chess as measure of the advantage. A centipawn is equal to 1/100 of a pawn. Therefore 100 centipawns = 1 pawn.These values play no formal role in the gamebut are useful to players, and essentials in computer chess, in order to evaluate positions.
The pieces have usually an integervalue in pawns, but using the centipawn allows strategic features of the position, worth less than a single pawn,to be evaluated without requiring fractions.
Standard ValuationThe following is the most common assignment of point values:- The queen is worth 900 - Each rook is worth 500; - Eachknight is worth 300; - Each bishop is worth 300; - Each pawn is obviously worth 100 centipawns.
The value of the king isundefined as it cannot be captured,let alone traded, during the course of the game. Some early computer chess programs gave the king an arbitrary large value (such as 100,000,000 centipawns) to indicate that the inevitable loss of the king due to checkmate trumps all other considerations. In the endgame, when there is little danger of checkmate, the fighting value of the king is about four pawns. The king is good at attacking and defending nearby pieces and pawns. It is better at defending such pieces than the knight is, and it is better at attacking them than the bishop is.
So, even if you are a superior player to the computer, you will still have an Average Difference value, since the computer may find a move that is part of your plan or strategy disadvantageous to gaining centipawn value (according to its programmed formulas). That is to say, the rating of the computer doing the analysis must be known for the Average Difference value to have full meaning (especially if you are a high-rated player, which I am not). This makes sense to me, anyway, but I didn't know what the Avg. Diff is until I came to this page, so, maybe efinitelynotverygood can enlighten us some more...
Busted_Bicycle
Stockfish, the chess engine chess.com uses for analysis, is the best chess player in the world - so there are no superior players to the computer. Everyone has an average difference value because no human player makes the correct moves, ever.
If you are Bobby Fischer and make every correct move, then is your average difference 0 (is an average difference of 0 possible)? Also, is it a good goal for players to lower their average difference between games, or is the number too flexible and unpredictable where say, for instance, one really bad move increases the avg. difference by as much as three wrong moves in a different game? Thanks in advance.
Andrew-Dufresne
I'm no expert, but this is what I have gathered.
Bobby Fischer would not make every correct move; that's basically impossible for any human player. But if he did play all the engine moves then it would by definition give a 0 centipawn loss average.
Looking at centipawn loss is a fun way to consider your play standard, but like you said, each game is different and even something like playing against a stronger player could make your loss worse. It would be kinda interesting to track the game to game changes of player centipawn loss though, however, I couldn't see it being a reliable progress metric.
If one made a material or positional blunder your loss would also balloon. Looking at the last game I played, I played the engine "correct" moves around 60% of the time but because I failed to take advantage of an opponents positional blunder on 2 occasions, I was considered to have made a mistake. Hence, my average centipawn loss was closer to 0.55.
Dec 16, 2017
0
#10
@xifong @andrew The centipawn is about calculating a position, not a move. However the centipawn difference is calculation the difference between two positions. aka a move.
In chess white win more times than black so white actually starts with a centipawn advantage. aka a better position, but other than that an equal position would give a 0 centipawn advantage to either side. If one side loses a pawn that color get a -100 centipawn disadvantage, while the other get +100 advantage.
Not only material translates to centipaws. A better position also gives exstra centipawns.
Jan 14, 2018
0
#12
festusmaximus wrote:
i played a game where i destroyed my opponent, but had a significantly higher avg diff, how common is this?
mine was 2.44 as opposed to his 1.03
Did your opponent make a big blunder at some point? That could be the case if on average your position was worse than his.
I notice the same thing when I play the chess computer on this site at level 5. The computer's average difference is almost always 0.4 points better than mine when I nonetheless win. So my moves are worse, but still, somehow they add up to victory. I suspect the problem is that the computer is doing a snapshot evaluation of a succession of positions, but is not paying attention to the overall strategy which is motivating that succession.
Jan 21, 2018
0
#14
I'm not sure about Chess.com's Avg diff. I analyzed this same game on both lichess and chess.com. Chess.com said I had an av diff of 1.00, whereas lichess said I had 3 cpl. I'm not sure how it works. https://lichess.org/k3VU3w0O/black#0
My average difference is also highly unstable, ranging from 0.50 to 2.4, suggesting that it is not a very accurate indication of a player's characteristic strength, but just of individual game performance.
Oh yes it can be greater than one, unfortunately, as I can attest from my own experience. But something I find quite often which seems strange is that my average difference in a game can be much higher than the computer's, even though I still beat the computer. So I am consistently making worse moves which somehow add up to a victory. Does the machine, in assigning average difference ratings, not notice how apparently sub-par moves are adding up to a deeper plan in terms of which they are more sensible?
What is the approximate correspondence between a player's average difference score and a player's rating?
Jun 12, 2018
0
#19
There is no comparison, because average difference varies greatly from game to game, and it depends on the opponent. Two players of approximate strength will likely have high average difference, whether it's two 1200s or two GMs
| The definition of the chess-db.com play quality index is inspired by the work of Matej Guid and Ivan Bratko on analyzing quality of play in chess games. For a comprehensive overview and technical discussion on this topic one can read their paper Using Heuristic-Search Based Engines for Estimating Human Skill at Chess, 2011. In short, the method compares the moves which were played in a chess game with the ones that a strong chess engine would play. The average difference of the evaluation of the moves played with the ones suggested by the engine is used as the indicator of how "good" the game was played. More detailed, yet short description of the method is the following:
This article will be continiously extended with further examples that demonstrate the method and the results it produces for notable chess players and tournaments, as well as further technical details regarding the calculations we carried out. |
As our calculations are progresing (as of January 2016, we have fully analyzed over 100,000 chess games) we can already make some observations. One is that the play quality index of the players correlates with players' ELO ratings, even only if as little as just few games per player are taken into account. While exact statistical analysis still has to be done, the practical result we expect out of this finding is that we can estimate player strenght and performance in tournaments much faster (accurately) than ELO formulas would when only few games of a player are available. The graph below shows the quality of play index (Scaled, so that it can be easily correlated with the ELO rating graph). The QoP index graph is very closely correlating with ELO rating for the range of players that has at least 10 games analyzed. At the tail (for players with ELO rating smaller than 2300) the correlation still exists but the variance is higher. This is basically because much less players and their games have yet been analyzed in those ranges. |
Played my first game on chess.com and clicked on the Quick Analysis button. What exactly does the Average Difference column mean? Mine was 0.84 while my opponent's was 0.72.