aller sans dire bank on be axiomatic be certain be confident bet on calculate on chance chance it count on depend on doubt not feel sure go without saying have no doubt hazard just know know know for certain lean on place reliance on reckon on rely on rely on fortune rely upon repose on rest assured rest on risk run a chance run the risk set at hazard swear by take a chance take a flier take chances tempt fortune trust to trust to chance try the chance venture wager