As often as not
Definition 1 of 1
Pro Tip 1/3Frequency Context
Use it when describing events that happen almost half the time, but not always. 
As often as not, we have leftovers for dinner.
Pro Tip 2/3Indicates Uncertainty
Suggests that there is no guarantee something will happen, but there's a good chance. 
He’s late to meetings as often as not.
Pro Tip 3/3Conversational Tone
It's casual and fits best in spoken English or informal writing. 
As often as not, I'll choose a comedy over a drama.