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standard practice; playing by the book; established tactic; formula
joseki (jōseki); standard sequence of moves (esp. in a corner)
囲碁の定石を覚えるのに苦労した。
I had a hard time learning standard go openings.
まず定石に沿って打つ。
First I play following the standard openings.
定石通りにやれば大きな失敗はしない。
If you follow the established approach, you won't make big mistakes.