also: だいぶち
noun
proxy gambler; playing on behalf of someone
Refers to a person who gambles (especially mahjong or pachinko) as a substitute for another person or organization, or the act itself. Often used in contexts where the real player cannot or does not want to appear directly.
彼は社長の代打ちとしてパチンコで大金を使った。
He spent a fortune playing pachinko as a proxy for the company president.
代打ちを頼まれて、初めて麻雀を打った。
I was asked to be a proxy gambler and played mahjong for the first time.
Compound of 代 (substitute) and 打ち (hitting/striking, from 打つ). The term likely originated in gambling contexts where a person 'hits' tiles or balls on behalf of another.