Among the various requirements to sit in an arbitral panel, impartiality is certainly one of the quintessential. Students of international commercial arbitration are often told in their first lecture that arbitrators must be and remain independent and impartial, and most arbitration rules include the requirement of impartiality of arbitrators in some form, whether explicit or implicitly (see e.g. UNCITRAL Rules 2010, Art. 12; ICC Rules 2012, Art. 14(1); ICDR Rules, Art. 8(1); HKIAC Rules, Art. 11(4); LCIA Rules, Art. 10(1) and (3); CIETAC Rules 2012, Art. 29(2); SIAC Rules 2010, Art. 11(1)). The said rules, however, seldom provide for any proper indication of what the parties should expect from the arbitrators, especially those they appointed, in terms of impartiality. According to Redfern and Hunter (p. 254) 'the concept of "impartiality" is considered to be connected with actual 4.78 or apparent bias of an arbitrator - either in favour of one of the parties, or in relat...