Depends on what you're searching for. For position lookup, there's an index; for something like a given player, it's likely to be a linear scan. Some format do

Depends on what you're searching for. For position lookup, there's an index; for something like a given player, it's likely to be a linear scan. Some format documentation: https://web.archive.org/web/20160329061708/http://rybkaforum.net/cgi-bin/rybkaforum/topic_show.pl?tid=2319 https://web.archive.org/web/20160329061708/http://rybkaforum... http://talkchess.com/forum/viewtopic.php?topic_view=threads&p=287896&t=29468 http://talkchess.com/forum/viewtopic.php?topic_view=threads&...