user23278: [FEN "1k5r/p1p2pq1/2n5/1p1p3n/1P1Pp2Q/P1P1P1P1/1B1K2B1/7R b - - 0 1"]

Today I was playing a game with myself only. This is the condition now it is black to move. What can be the best move in this situation?

user12398: In the present position black cannot move the knight, and it appears white is threatening to attack it with g4 but in fact if white plays g4 he won't be able to capture the knight with the pawn without losing the bishop n g2.
...Rh7 is one way to allow the knight to move away to f6 but it is not necessary to play that right away and you could play a move like ...a6 first.

user4182: The knight on h5 is pinned to a rook, and faced with the potential threat of g4. To unpin this knight, Black should play Rh7, so that the knight is free to go to f6 (where it will protect the rook).
[FEN "1k5r/p1p2pq1/2n5/1p1p3n/1P1Pp2Q/P1P1P1P1/1B1K2B1/7R b - - 0 1"]

1...Rh7 2.g4 { This move is just for illustration, and probably not best. } Nf6 

I would argue that Rh7 is the best move in this position. It has been stated in a comment that Stockfish marginally prefers a6 to Rh7 (although it always prefers Rh7 when I try it, at all depths from 3 to 46 - it probably depends on cache state, number of threads, etc.). But from a human point of view, I don’t think a6 makes much sense: all the while the pin exists, White can try to find ways of exploiting it; Black ought to put a stop to this right now. In fact, the main purpose of a6 (from Stockfish’s point of view) seems to be to deal with one possible way of exploiting the pin; but clearly it’s simpler just to remove the pin.

23278: <pre><code>[FEN "1k5r/p1p2pq1/2n5/1p1p3n/1P1Pp2Q/P1P1P1P1/1B1K2B1/7R b - - 0 1"]
</code></pre>

<p>Today I was playing a game with myself only. This is the condition now it is black to move. What can be the best move in this situation?</p>
 12398: <p>In the present position black cannot move the knight, and it appears white is threatening to attack it with g4 but in fact if white plays g4 he won't be able to capture the knight with the pawn without losing the bishop n g2.</p>

<p>...Rh7 is one way to allow the knight to move away to f6 but it is not necessary to play that right away and you could play a move like ...a6 first.</p>
 4182: <p>The knight on h5 is pinned to a rook, and faced with the potential threat of g4. To unpin this knight, Black should play Rh7, so that the knight is free to go to f6 (where it will protect the rook).</p>

<pre><code>[FEN "1k5r/p1p2pq1/2n5/1p1p3n/1P1Pp2Q/P1P1P1P1/1B1K2B1/7R b - - 0 1"]

1...Rh7 2.g4 { This move is just for illustration, and probably not best. } Nf6 
</code></pre>

<p>I would argue that Rh7 is the best move in this position. It has been stated in a comment that Stockfish marginally prefers a6 to Rh7 (although it always prefers Rh7 when I try it, at all depths from 3 to 46 - it probably depends on cache state, number of threads, etc.). But from a human point of view, I don’t think a6 makes much sense: all the while the pin exists, White can try to find ways of exploiting it; Black ought to put a stop to this right now. In fact, the main purpose of a6 (from Stockfish’s point of view) seems to be to deal with one possible way of exploiting the pin; but clearly it’s simpler just to remove the pin.</p>
