Ahh, this is super nice!

One thing I'd love to know or see is common mistakes I make or the type of mistake/trap I fall into in the pivotal moments of games (some kind of fork/pin combo for me I suspect) ... and/or repeated mistakes I've made in the same position.

I'm currently not doing Stockfish evaluations (everything is based on simple win/loss-rate) but I hope I'm able to integrate this in the future. Then I can show much more in-depth statistics like the one you mention.

The scroll feature to rewind/forward moves on a game, with syncing the state in the URL, is just awesome.

Do you mind sharing how it's done? I just published a library [1] that deals with syncing complex state in the URL, and I'd love to hear more about actual use-cases in the wild.

[1] https://github.com/47ng/next-usequerystate

Thanks, I just like it when all state is in the URL and you can just bookmark it. Also using the browser back/forward button should work well thanks to that. I'll check out your library!

My code for that is rather simple. I'm using Next.js and the code looks something like this (a little simplified):

  const router = useRouter(); // get the router/location object
  const information = useFetch({ position: router.query.position }); // fetch information from the server
  
  function changeChessPosition(newPosition) { // called when position changes
      router.replace({ query: { postition: newPosition } }); // replaces the state in the URL
  }

In addition, I have some caching in place so that each position is only downloaded once and the change function looks a little more complicated in my case as there are multiple values that can be change for each page.

It seems like Lichess already has most of the features on the site; they have a better UI on ChessMonitor though.

The main killer feature I see is combining multiple accounts. Are there any other features didn't notice?

There are many similar features. Overall the UI on ChessMonitor is much more focused on statistics.

Another key feature Lichess does not have, is the Openings page. It is very powerful when used correctly. You can look at your openings and immediately see for which openings you might need to consume more theory (or which you should not play at all).

Here is an example: https://www.chessmonitor.com/u/cdPiOkUArRJ7shVNJcT3/openings...

Would like to see Chess960 variant stats.

Classic chess are way too predictable and players who've managed to learn popular openings have an advantage. Chess960 fixes that.

And due to comparably low popularity of Chess960 I often play it with Stockfish. It has several difficulty levels which are a convenient tool for practice.

So it would be nice to include games with bots (checkbox?) on ChessMonitor as well.

I'm aware of Chess960, but this will probably never be supported on ChessMonitor for three reasons: First, Chess960 basically tries to prevent players from preparing (by having a random starting position) which does not align well with providing statistics. Second, it would require major UI and storage changes on ChessMonitor (like adding an option to select the starting position to compare games). And third, Chess960 is simply not as popular amongst non-professional chess players.

How many combinations are there for Chess960?

I'm wondering whether people could also prepare for it if it became popular.

There's 960 of them. Hence, the name.

Slight nuance: the 960 figure includes the regular starting position, and there's some variation in different tournaments about what would happen if the classical starting position were selected. So, at least in some tournaments, it's actually Chess959. But I guess that has less of a ring to it.

This is the most beautiful site I've seen in years.

My only criticism is the search box's height seems to be a few pixels shorter than the search button.

Do you write about design or development anywhere, or have a GitHub profile? I didn't see anything linked in your profile here.