actually, i might be mistaken -- i'm not sure they charge you for money going out.

mgr = monthly gross revenue (i.e., your rake). rb is calculated based on mgr. as of december, rake is deducted from mgr. bonus is, of course, deducted from mgr. on sites like ft, any ft points you use are also charged against your mgr.

anyway, ed's initial equation most likely the correct one. i just did a withdrawal from cake about a week ago, and nothing has been deducted from my mgr yet.