99% sure
A phrase used when you think something is right but you really don't know jack shit.
Guy 1: Is my wife home from here business trip yet? I'm planning on bringin' some chicks over for a party.
Guy 2: I'm 99% sure she isn't.
Wife: I've been here all fucking day you asshole.
Guy 2: I'm 99% sure she isn't.
Wife: I've been here all fucking day you asshole.
99% sure
When you're sure but don't know for a fact
I'm 99% sure that's not what he meant