there are many definition of BIS .. some players are almost BIS but they are not dishing out the dmg they should, it depends on the class you choose, there are some class, even with good gears (not BIS) they can macro and kill an enemy (especially healers) within 3-4 seconds, i had tried it on my hunter (using all gears higher than 184, trinkets not included because BOE trinkets are bad), i experiment on this just for the purpose of helping my team rid the enemy healer, but a hunter when caught up by a few enemys with CD blown is too easy to kill, on the other hand i have blood dk and ret pally and shaman and mage and druid and priest having the so called ilvl204 - 224 gears, yes, always top dmg in bg, but they just cannot kill a heal, dont say 3 seconds, give them 10 mins they would still not be able to kill a healer single handedly .. i have 4 hunters in the 100-109 brackets all of which are BOE geared .. the next thing i want to try out is how 4 hunters perform in the same bg, more or less i know what the outcome will be, just waiting for my kids to be available to bg with me .. for the information, in my test for the hunter's burst, the only class that can always survive 1 round of attack is a blood DK as their health is usually over 28k at lvl100-109 .. it will need 2 hunters to burst him out .. other tank classes, some can survive some cant, i dont know why, but a blood DK always survive, and this hunter burst can be repeated after 1 min, but it will be a semi burst, to get a full burst again, it requires 2 mins for all CD
forgotten to add, some classes has instant full heal, like a pally and some classes has full immune to dmg for a few seconds, but once they use this, they will have to wait for a few mins to reuse that ability, my second burst will come before they get their defense up again, these are usually players who had been killed before and they are readied for it, but for new players i encountered, the burst kill happens so fast they wouldnt have time to react to it
i have also encountered healers telling their team mates to stop my burst using fear silent etc .. so these days i am doing it outside their range, this burst dmg takes place at a max distance of 68 yards .. thats the hunters max attack range
a lvl99 hunter can perform the exact same thing, but not a lvl89 hunter