The author maintains that the key to efficiency in arbitration does not lie in the arbitrator’s purely procedural, external, quantitative intervention, consisting in pruning deadlines or probative possibilities, but rather in an adequate and early qualitative intervention, which can contribute to harmonize disparate legal and terminological elements, clearly set the terms of the debate on the merits of the dispute, and trace the channels through which this debate will run. In addition, since arbitration is truly a justice system, efficiency requires the participation of all those who intervene in the arbitration process: counsel, arbitrators, and especially judges. The greater or lesser efficiency of arbitration is dependent on the loyalty of each and all of them to arbitration as a process and as a system.