The phrase "leaderboard position" refers to a person's or team's ranking or position on a list that shows who is currently the best or most successful in a particular competition or activity. Full definition
Unit 13's live notification interface, enabled through 3G, keeps players up to date on leaderboard positions, new «Daily Challenge» content, new unlocks, shared High Value Target missions, and challenges from friends as they move past you on the leaderboards. (blog.us.playstation.com)
Forget those fleeting leaderboard positions and ultimately pointless achievements - this is about beating your backlog. (gamesradar.com)
All players in the # 1 leaderboard positions at that point will be confirmed as a Guinness World Records title holder and sent an official certificate! (guinnessworldrecords.com)