It varies but it generally seems to most often be a 2.66x payout, it's difficult to follow his bet pattern it is pretty distinct.

The house sustained a significant loss today, somewhere between 500-600 coins due to massive risk taking from today's whale(s) who persistently deposited 10-25 coins at a time until turning individual deposits into 300+ coin gains on multiple occasions.

Grats to him on turning around some significant losses.  


EDIT: He's doing some pretty significantly bets currently, check out the highroller tab to keep an eye on the action