Opening Tree is a free web tool that pulls your game history from Lichess or Chess.com and builds a personalized opening explorer from your results. Rather than showing theoretical statistics from master games, it shows you what you personally have played, how those lines have performed, and which openings are hurting your score.

The interface presents your openings as an interactive tree: click any move to drill down, see your win/draw/loss percentages, average opponent rating, and number of games. You can filter by time control and color, making it easy to identify the openings you default to in blitz versus classical games.

Opening Tree requires no account or installation — just enter your username and select the platform. It is a practical first step for any player who wants to understand their actual opening tendencies before investing time in memorizing new theory.