user24788: Is there a tool to display how many times a certain move has been played?
Note that I do not mean openings, I mean specific moves. Moves that I am looking for would be castling with checkmate or underpromotion to a knight with checkmate, and similar things. Is there a tool available to search for something like that?

user4418: Chess Query Language operates on PGN files of games and does what you want as well as much more powerful stuff. It is a free download. There are lots of examples to get you started here.

24788: <p>Is there a tool to display how many times a certain move has been played?
Note that I do not mean openings, I mean specific moves. Moves that I am looking for would be castling with checkmate or underpromotion to a knight with checkmate, and similar things. Is there a tool available to search for something like that?</p>
 4418: <p><a href="http://www.gadycosteff.com/cql/" rel="nofollow noreferrer">Chess Query Language</a> operates on PGN files of games and does what you want as well as much more powerful stuff. It is a free download. There are lots of examples to get you started <a href="http://www.gadycosteff.com/cql/examples.html" rel="nofollow noreferrer">here</a>.</p>
