What is the probable cause requirement for an arrest warrant?

Illinois v. Gates (1983) 462 U.S. 213, characterized the probable cause requirement as follows: "The task of the issuing magistrate is simply to make a practical, common-sense decision whether, given all the circumstances set forth in the affidavit . . . , including the `veracity' and `basis of knowledge' of persons supplying hearsay information, there is a fair probability that contraband or evidence of a crime will be found in a particular place." (Id. at p. 238.) "Long before the law of probabilities was articulated as such, practical people formulated certain common-sense conclusions about human behavior; jurors as factfinders are permitted to do the same and so are law enforcement officers." (Id. at pp. 231-232.)