Synonyms to toss up

blind bargain, borderline case, chance, chance at odds, contingency, double contingency, even break, even chance, fair shake, fifty-fifty, gamble, gambling chance, guess, half a chance, matter of chance, odds, open question, piece of guesswork, potluck, potshot, question, random shot, sight-unseen transaction, sporting chance, square odds, standoff, toss, touch and go, undecided issue, wager