likely as not

*likely as not

Fig. probably; with an even chance either way. (*Also: as ~.) He will as likely as not arrive without warning. Likely as not, the game will be canceled.
See also: likely, not
References in classic literature ?
It is a very amusing and egotistical occupation of no use whatever to any one and just as likely as not to lead to false conclusions.
It was not a love of the grandiose or the prestige attached to the command of great tonnage, for he continued, with an air of disgust and contempt, "Why, you get flung out of your bunk as likely as not in any sort of heavy weather.
He would soon have been up with the hounds again, when the fatal accident happened; and hence he was between eager riders in advance, not troubling themselves about what happened behind them, and far-off stragglers, who were as likely as not to pass quite aloof from the line of road in which Wildfire had fallen.
To gratify Jansenius I waived this objection, and only interfered to save him from being fleeced and fooled by an unnecessary West End middleman, who, as likely as not, would have eventually employed the very man to whom I gave the job.
If she has any to spare, it's as likely as not to be wasted on her good-for-nothing husband.
He also is a stranger and likely as not they both hail from Helium, and where one is we shall sooner or later find the other.
As likely as not, the General knows more about Mlle.
I have no doubt that he has twenty banking accounts; the bulk of his fortune abroad in the Deutsche Bank or the Credit Lyonnais as likely as not.
If little Phoebe was about the house, I should not mind knocking; but Miss Hepzibah, likely as not, would scowl down at me out of the window, and look cross, even if she felt pleasantly.
Chance was as likely as not to carry me into the very corridor they might choose to enter.
It's just as likely as not,' said Bob,' one of these days; though there's plenty of time for that, my dear.
And as likely as not she belongs to gentlefolk too, poor ones maybe.
Put to rest in Davy Jones's locker this many a day, as likely as not.
We after the convict, and a hell-hound, as likely as not, after us.
He used to make it at all sorts of times; as likely as not after he had been listening to little Lena's chatter about the suffering doll, for instance.