I came upon chess.com playing against computer mode. I found a resemblance of two professional chess players over there. Do they really resemble their gameplay, though? Does the AI mimic their past plays?
I have spent some time playing the lower-rated bots, and can confirm they tend to have different "personalities". I'm not a strong enough player to explain exactly how they are different. However I have observed that some are more aggressive, and tend to gravitate towards particular openings depending on the color.
I know that Hikaru recently did a series of videos on youtube where he played against bots. When I saw the new bots, I had a feeling that it was for the purpose you describe.
We don't know for sure. Chess.com is closed source so we will never know for sure. One thing I can tell you for sure, you're NOT playing the real Nakamura. It's nothing more than a tuned chess engine wrapped by smart marketing.
Why don't we take a look of PlayMagnus https://www.reddit.com/r/chess/comments/a5ws9t/question_about_playmagnus/?
The higher levels of the app actually makes some attempts to play like Magnus did at the various ages. It isn't nearly as good as I would like it to be (I was handicapped by an extreme shortage of development time and not having anything better than my MacBook available for tuning and testing), and I hope to find the time to do a better job some day, but at least it is true that analysis of Magnus' style, strength and opening choices through the years played some role in the development of these levels.
The lower levels, however, are pure fiction. We didn't even have any games played by Magnus at these ages. We made these levels with the aim that every chess player - even someone who has just learned the rules - should be able to find some beatable level. Magnus 5, the lowest level of all, plays completely random legal moves. It has nothing to do with any research of how Magnus or any other 5 year old plays chess.
So think of like paying chess.com for a new careful strong tuned chess AI. Sorry, no Nakamura here.
I don't know what exactly was tuned. My guess:
- Playing strength
- Thinking time
- Static evaluation
- Search algorithms
- Piece square tables
- Search depth etc