Birthday problem is 70.6% with 30 people (according to the
Wikipedia link posted above).
W/r/t the $1500 PLO8 field, i can confirm it's a soft field. My initial table was fantastic.
That said, Hellmuth came in 14th in the same event last year (7th this year). He's still not very good at the game. Last year, he twice raised pre-Flop with AJ52 with the suited ace and folded to a Cantu re-raise after a even though he started the hand with only 7-9 BBs. Even though Cantu had AA both times (including once with AA2), that's a bad play. Cantu had been playing like a crazy person all day.
Then again, Hellmuth did outlast me both years (me: 17th in 2009, 35th in 2010) including (basically) knocking me out this year with a UTG limp re-raise with AA32ss (he had 6 BBs and i only had 7 BBs).
There were several other repeat deep runs in the $1500 PLO8, including 2010 winner Steve Jelinek, who came in 6th last year. Of course, the multiple deep runs in the same event is a variation of the birthday problem.
Finally, i think that Hellmuth is a clear favorite to win a non-Holdem bracelet over Ivey winning a NL Holdem one. Not only do the non-Holdem events have smaller fields, but Hellmuth enters many more non-Holdem events than Ivey enters NLH ones. I'm rooting for Ivey.