Under Cal. Rules of Court, rule 3.516, in a coordinated proceeding, a 170.6 challenge to the coordination trial judge must be filed within 20 days after that judge has been assigned to the coordinated cases. The rule also specifies that all plaintiffs in all the coordinated cases are deemed “one side” and all defendants another “side” for purposes of the rule that there is only one 170.6 challenge per side. This decision rejects the defendants’ argument that the rule actually allowed a separate 170.6 challenge for each separate coordination proceeding. Instead, since one defendant had exercised a 170.6 challenge before the cases were coordinated, the defendants could not exercise another 170.6 challenge after the cases were coordinated and assigned to a different coordination trial judge.