one's greatest strength; what one is best at
Emphatic expression meaning the very best among one's areas of expertise; often used when someone is extremely confident in a particular skill.
数学は彼の得意中の得意だ。
Mathematics is his absolute forte.
料理なら得意中の得意です。
When it comes to cooking, it's my strongest suit.
A set phrase combining 得意 (one's forte) with the emphatic pattern 〜中の〜, literally 'the forte among fortes'.