user16626: In the video "ugly defense", GM Grigoyan called the move Knight g3-h1 an "ugly move", though objectively speaking, Nh1 may be the best move for white in this position.
[fen "r1b2rk1/b1p4p/p1pp1qp1/P7/4P1n1/3N2N1/1PP2PPP/R1BQ1RK1 w - - 1 1"]

May I know if there is a definition of an "ugly move"? In my humble opinion, if a move is objectively the best in a particular position, it should be called a "good move", or sometimes a "brilliant move", or sometimes a "forced move", or sometimes a "book move". In this position, I would call Nh1 a "forced move".

user4418: An "ugly move" is one which violates positional principles. Here the knight on g3 attacks / defends 6 squares - h5, f5, e4, e2, f1 and h1. On h1 it only attacks/ defends 2 squares - g3 and f2. Positionally it is much better on g3 than h1. However tactically f2 is key because it is attacked 4 times, pinned against the king and only defended 3 times. It is a far more important square than all the 6 squares the knight can reach from g3. Although Nh1 is an ugly move it is also a necessary and good move. These terms are not mutually exclusive.

16626: <p>In the video &quot;<a href="https://www.youtube.com/watch?v=SJaM93TUD8A&amp;list=PLBEZDOS8vWC1-VyG0rLkAUzgZaXhGwHJk&amp;index=115&amp;ab_channel=ChessMood" rel="noreferrer">ugly defense</a>&quot;, GM Grigoyan called the move Knight g3-h1 an &quot;ugly move&quot;, though objectively speaking, Nh1 may be the best move for white in this position.</p>
<pre><code>[fen &quot;r1b2rk1/b1p4p/p1pp1qp1/P7/4P1n1/3N2N1/1PP2PPP/R1BQ1RK1 w - - 1 1&quot;]
</code></pre>
<p>May I know if there is a definition of an &quot;ugly move&quot;? In my humble opinion, if a move is objectively the best in a particular position, it should be called a &quot;good move&quot;, or sometimes a &quot;brilliant move&quot;, or sometimes a &quot;forced move&quot;, or sometimes a &quot;book move&quot;. In this position, I would call Nh1 a &quot;forced move&quot;.</p>
 4418: <p>An &quot;ugly move&quot; is one which violates positional principles. Here the knight on g3 attacks / defends 6 squares - h5, f5, e4, e2, f1 and h1. On h1 it only attacks/ defends 2 squares - g3 and f2. Positionally it is much better on g3 than h1. However tactically f2 is key because it is attacked 4 times, pinned against the king and only defended 3 times. It is a far more important square than all the 6 squares the knight can reach from g3. Although Nh1 is an ugly move it is also a necessary and good move. These terms are not mutually exclusive.</p>
