user5784: The most terrible blunder is to resign in a won position.
How can I systematically search for such games ?
How often does this happen if both opponents have, lets say, at least ELO 2400 ?

user291: There is a comprehensive list on Tim Krabbé's page The Ultimate Blunder.

5784: <p>The most terrible blunder is to resign in a won position.</p>

<p>How can I systematically search for such games ?</p>

<p>How often does this happen if both opponents have, lets say, at least ELO 2400 ?</p>
 291: <p>There is a comprehensive list on Tim Krabbé's page <a href="http://timkr.home.xs4all.nl/chess2/resigntxt.htm" rel="noreferrer">The Ultimate Blunder</a>.</p>
