a cinch - Something so sure it might as well be written in the sky wit

Something so sure it might as well be written in the sky with glitter and a middle finger.

That movie was a cinch. I knew it was going to be good before it even started.

She said she'd come. That was a cinch. I knew she'd show up.

That was a cinch. I knew I'd win the bet before I even took it.