Biught pack and never got boss. In fact have spent maybe 60k stars 40k on elite and 20k on normal and no boss. Not to mention that in the past only getting like 3 hits on boss before gone. This makes labyrinth useless to most as its not worth it from the items you get. Is it just bad luck for me or same for others.
As someone who won the small jackpot, I can tell you it's complete luck. Probably spent a total of 500k stars before winning. The day I won I had only spent 6k. I won 1.5 mil gems. I bought 400k more stars and spent them all in the same day and didn't win again.
Its like more u spend higher chances u have
Try to always Hunt on elite during events for better results
Its sheer matter of luck buddy
Doing complex mathematics at the probability of killing boss will do u no good
Only thing favourable will be Get set go
keep trying ;-)