Game report differs from my opponent

Hi!
I recently finished a game of chess and for some reason my game report differs from my opponent's report of the very same game. For example is the accuracy and the number of best moves different in our two reports. What is the explanation behind this?

How big are the differences?

All the reports depend on how much processing power is used. Numbers of blunders, etc., are determined by numeric cutoffs. Slight differences can result in blunders being classified as mistakes and so on.

Given what you said I can see that the differences came down to what we could call the "detailed classification", while the overall number of "fine" and "bad moves" remain the same between the reports. For example, in his report one of my moves was "Brilliant" while in my report it probably fell under the category "Excellent". When it came to accuracy my report gave me 92.4 and my opponent 86.3. In his report my accuracy was 83.3 and his 90.9.

But from what you are saying these differences are related to the hardware being used when initiating the game report?

Can anyone confirm whether these differences are within/outside the ordinary? Are these differences purely related to him using a PC and me playing on my phone? PS. We are both premium users (me gold bad him platinum) if that matters.

The analysis is carried out on your client (not on the server). So yes, if one player is using a decent PC and the other player is running the app on a potato, the results can be wildly different.

Haha, fair enough. Thank you!

Posted from my root vegetable.

Is it done in the client? According to chess.com's help docs: 

"The game report and positional analysis are calculated in the 'cloud' meaning the analysis is done using Chess.com's servers. This means the analysis is much quicker and stronger."

How old is that info?

It's in their current docs. Click help, search for "game report," and look for the entry "What is analysis depth? What does it mean?" -- I'm no expert, but if analysis is done on the device when the analysis is run, I would want to re-check games when I'm on my desktop.

I had some analysis change after I got my i5. A game that I'm quite proud of that was rated 99.4% accuracy and 1 brilliant move became 99.0% accuracy and no brilliant moves.

Could be just coincidence, of course. Maybe chess.com updated something just about the same time.

It looks like they went to the cloud in early 2019. From this post (https://www.chess.com/blog/News/meet-the-new-analysis-game-report-retry-mistakes-more): 

"Finally, a note on the strength of the analysis this feature offers, because this is a huge difference between the new Analysis and the old. The "full" analysis that runs on your game to create the report, analysis data, and Retry Mistake positions is extremely fast. It is better than the old analysis you used to wait for, because instead of leaning on client-side/browser-based tech, the new analysis is done by a large cluster of server-side engines."

Yes, but there's at least two different analysis modes.

Example: Look familiar?

... but when I hit analyze:

I get different numbers. Is mine the "cloud" analysis and your local? Or perhaps vice-versa?

So different devices should be of no factor then.

And as you said, if it was, you would want the option to re-run game reports.

> I get different numbers. Is mine the "cloud" analysis and your local? Or perhaps vice-versa?

I have no idea and can only go by what chess.com tells me/us. Given that both differences are .1 in the same direction, it could be the way they are rounding for display?

Also, there is this settings screen from the analysis window that implies both game analysis and report are done in the cloud, while real-time move analysis is in the browser/app, which makes sense to me:

For more than that, you'd need to go to chess.com's help.

EDIT to add: It seems telling to me that the depth-based analysis takes apparently the same time whether I am on my desktop or my iPhone 5 (I know, I'm a monster). I don't see a way to test more accurately since I can't see a way on my phone to re-run the analysis at a different depth. But it is clear that self-analysis and real-time analysis while watching a game are run locally.