1. Scan the opponent’s games using a chess database or (at least) the games from the tournament – usually available online. Pay a lot of attention to his/her openings. Try to understand what positions he/she prefers, and which he/she plays badly. If you have enough time, try to compile a complete dossier on him/her – psychology, weaknesses and strengths in chess, current chess shape, physical shape, motivation, time management, etc.
2. Depending on a variety of factors (tournament situation, opponent’s style, your own wellbeing) you can choose an opening variation (or a few of them, depending on how broad your opponent’s opening repertoire is).
3. If necessary, study the variation in more detail, try to find new ideas.
4. Rehearse the lines before the game (normally the higher the level of a player, the longer it takes).
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