Enterprise Wheel permits judicial scrutiny of labor arbitration awards to determine whether an award draws its essence from the collective bargaining agreement. The imprecision of that standard of judicial review has resulted in courts straying into the interpretation of pertinent contract terms when considering challenges to the enforcement of an award. Although reviewing courts are to limit their inquiry to identifying and enforcing explicit contractual limitations on arbitral power, courts frequently engage in a review of the merits of the substantive dispute and merely substitute their interpretation of contract language for the arbitrator’s.