I'm using Stockfish to analyze my blunder filled games for blunders.
Let's say you send stockfish a FEN for a position and then calculate to a given depth ...
position fen the-starting-position go depth 15
Now let's say a move has been made. I can either send stockfish the move...
position move the-move
or send it the fen that results from the new move.
position fen the-postition-after-the-move
Is Stockfish more efficient when you send it to the former? That is, does it remember the evaluation from the starting position and use it as a starting point for analyzing the new position after you give it a 'position move ...' command? And does it not remember the prior calculations if you just send it the next FEN in the sequences?
And a similar question. If you tell Stockfish to analyze to a depth on a position, and then tell it to analyze to a deeper depth, does it start that second analysis from where the prior analysis stopped?
position fen the-starting-position go depth 15 go depth 20