expression, noun which may take the genitive case particle 'no'
sink or swim; all or nothing; hit or miss; make or break
Describes a risky situation where the outcome is either complete success or total failure, with no middle ground. Often used adverbially with で or as a の-adjective.
一か八か、その計画に全財産を賭けてみた。
I took a sink-or-swim gamble and bet all my money on that plan.
一か八かの勝負に出るしかなかった。
I had no choice but to go for an all-or-nothing contest.