user23898: 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?


user24319: 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.

user825: 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


user23898: They said about individual bot (strengths and weaknesses) but haven't disclosed about the bots, representing professional players.


23898: <p>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?</p>
<p><a href="https://i.stack.imgur.com/vHSp2.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vHSp2.jpg" alt="Screenshot of the page" /></a></p>
 24319: <p>I have spent some time playing the lower-rated bots, and can confirm they tend to have different &quot;personalities&quot;. 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.</p>
<p>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.</p>
 825: <p>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 <strong>NOT</strong> playing the real Nakamura. It's nothing more than a tuned chess engine wrapped by smart marketing.</p>
<p>Why don't we take a look of PlayMagnus <a href="https://www.reddit.com/r/chess/comments/a5ws9t/question_about_playmagnus/" rel="nofollow noreferrer">https://www.reddit.com/r/chess/comments/a5ws9t/question_about_playmagnus/</a>?</p>
<blockquote>
<p>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.</p>
<p>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.</p>
</blockquote>
<p>So think of like paying chess.com for a new careful strong tuned chess AI. Sorry, no Nakamura here.</p>
<p>I don't know what exactly was tuned. My guess:</p>
<ul>
<li>Playing strength</li>
<li>Thinking time</li>
<li>Static evaluation</li>
<li>Search algorithms</li>
<li>Piece square tables</li>
<li>Search depth etc</li>
</ul>
 23898: <p>They said about individual bot (strengths and weaknesses) but haven't disclosed about the bots, representing professional players.
<a href="https://i.stack.imgur.com/oEg8B.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oEg8B.png" alt="" /></a></p>
