Originally from Practical Guide to International Arbitration

INTRODUCTION

The body of evidence before an arbitral tribunal serves as an essential element in every arbitration.  In-house lawyers tend to play a critical role in the early stages of the dispute-resolution process, identifying key custodians of evidence and shepherding the most important evidence to outside counsel for independent evaluation. To the extent that in-house counsel understand the role that evidence would play in the arbitral procedure, it will help them to adopt the most effective strategies for negotiation and dispute resolution. 

In general, factual evidence usually plays a decisive role in international arbitrations. As many as 60 percent to 70 percent of cases resolved by international arbitration turn on the facts themselves, rather than on the law governing those facts

Given that most international commercial disputes involve businesses from different legal traditions, it makes logical sense that most arbitral tribunals assessing those disputes prefer to focus on the evidence arising out of the dispute, rather than on abstract legal principles, which tend to vary from jurisdiction to jurisdiction.