just checked my database for figuring your chances out @d7...
maybethiscan help us:
got 1,2Million hands z500 in my database (WR ~2,5bb)
4out of the 12 100k-hand samples beat the 4bb/100 goal
taking into consideration that this is a challenge u will play more focused/less tables than me on average (not adding other zoomtables/lots of random midstakes tables) and should have a somewhat higher "true" winrate therefore.
So if my chance playing averagefocused/lots of 8tabling zoom was about 1/3 it should be possible to get up to 50%
I'm not the prob-bettingguy, but if I would I would give myself a 40% chance and selling for those odds (and expect this bet to be +EV for me)
Depends a lot on the time u're allowed to take, because timeselection is a big thing on z500...
If u don't have tough volumegoals u can pick the soft pools and get >60% chance on winning ur bet imo easily