expression
the enemy's key point is yours
A go proverb meaning that a vital point for the opponent is also a vital point for oneself; often used to emphasize that attacking the opponent's weakness can also strengthen one's own position.
See also: 急所
「敵の急所は我が急所」という格言は、相手の弱点を攻めることが自分の強化にもつながるという囲碁の教えだ。
The proverb 'the enemy's key point is yours' is a go teaching that attacking the opponent's weakness also leads to strengthening one's own position.
急所 means 'vital point' or 'weak point' in general, while this proverb specifically applies the concept in the context of go strategy.
A set phrase from the game of go; the exact origin is uncertain, but it reflects a fundamental strategic principle in go.