user16626: In chess, exclamation points ("!") indicate good moves and the double exclamation point ("!!") is used for very strong moves. However, I do not know any symbol for "best moves". There are moves which may not be surprising or involve any particular skill but are objectively the best move or one of the best moves in a particular position. With the help of modern engines, it may not be too difficult to see if a move is "the best" in a certain position.
When analysing games, one knows immediately that there is no room for improvement for such moves if such a symbol is used; isn't it convenient?

user18809: Moves that are significantly worse than the best option are annotated with ?!. If the difference between the move in a game and the "best" move is not big enough, then it doesn't matter whether some engine gives one a 0.02 better evaluation than the other.
In some sense, you could argue that !, !! and no annotation at all already indicate that the move played was the best possible option (or in the latter case, just as good as it)

16626: <p>In chess, exclamation points (&quot;!&quot;) indicate good moves and the double exclamation point (&quot;!!&quot;) is used for very strong moves. However, I do not know any symbol for &quot;best moves&quot;. There are moves which may not be surprising or involve any particular skill but are objectively the best move or one of the best moves in a particular position. With the help of modern engines, it may not be too difficult to see if a move is &quot;the best&quot; in a certain position.</p>
<p>When analysing games, one knows immediately that there is no room for improvement for such moves if such a symbol is used; isn't it convenient?</p>
 18809: <p>Moves that are significantly worse than the best option are annotated with <strong>?!</strong>. If the difference between the move in a game and the &quot;best&quot; move is not big enough, then it doesn't matter whether some engine gives one a 0.02 better evaluation than the other.</p>
<p>In some sense, you could argue that <strong>!</strong>, <strong>!!</strong> and no annotation at all already indicate that the move played was the best possible option (or in the latter case, just as good as it)</p>
