Winning streak

When you are part of a raiding guild, either hardcore or (semi-)casual you will know how frustrating is to be stuck on a boss. You might call it a losing streak but as you are stuck on one boss that might not be the right word for it actually, unless you give up and get pwned by an other boss aswell i guess. :P
But winning streaks, do those happen alot?

The first time we entered Karazhan we had sort of that winning streak i guess where we killed a couple of new bosses a night and more the following evenings. When Zul'Aman arrived another chance to get a streak arrived upon us, but when does a streak end? How does one work anyway?
If i kill a boss for the first time, how much time/how many chances do i have to kill the next first timer? Does the next boss i attempt have to go down before the night ends or can i come back later just as long as i don't do another boss in between? What if i do just that boss for weeks and weeks then before i kill it, is that still a streak? Or perhaps 1 new boss-kill per week is enough to call it a streak... i guess in the end it's just how you look at it.

I myself think we had a small streak this week tho; on Sunday we killed Lady Vashj in SSC and the next raidnight was yesterday where we went on to Tempest Keep. For those who know The Eye (which is the 25man raidinstance there) likely have guessed what boss we downed when checking out the picture i posted above; Al'ar!
This i quite a fun fight imo with an impressive looking boss, a flaming phoenix and killing it netted us with a short streak imo.
After the reset we will redo SSC and hopefully down Vashj again so we can move on to TK once more... if Al'ar goes down smoothly again (seems we know the dance now) we can try a new boss and if we manage to down it next week we still kinda are in that winning streak imho.

Back to Al'ar, the bugger dropped this crappy little trinket. I had myself a flashback to BWL all of the sudden where the Hunter trinket was nothing but a mere toy, sure this one i slightly better but as a BM i use my Arcaneshots limited most of the time and since the proc doesn't even effect Autoshot the dpsgain is not worth the loss of any of my other trinkets. The trinket is now a nice shiny little crystal in the guildbank.