Ciel hears some promising information: the ever-busy Head Master will be attending Weston's traditional cricket tournament, and evidently the student who exhibits the most sportsmanlike behaviour will be invited to the Head Master's "midnight tea party."
The lack of a clear standard means it will 
be most difficult to ensure he is chosen.
إنّ عدم وجود معيار واضح يعني أنّه سيكون
من الصّعب ضمان اختياره
Das Fehlen klarer Kriterien
Sin disponer de unos requisitos claros,
Sin disponer de unos requisitos claros,
Sans critère précis,
Non solo il criterio di selezione
non è prestabilito,
Por não haver um padrão claro,
Раз он всё решает по настроению,