WoW:API SetLootMethod
SetLootMethod("method"{,"masterPlayer" or ,threshold})
Arguments
"method" may be any one of the following self-explanatory and case insensitive arguments: "group", "freeforall", "master", "neeedbeforegreed", "roundrobin".
An optional final argument to any loot method is "threshold" which is an int value ranging from 0 to 6. The effect the threshold has varies based on loot method.
Threshold:
0 poor 1 common 2 uncommon 3 rare 4 epic 5 legendary 6 artifact
Additionally, if method is "master", the second argument must be a player name, followed by the optional third argument of "threshold"; e.g. SetLootMethod("Master","Hank",2) would set Hank as the master looter with an uncommon threshold.