Here is the SBR guide:
A- to A+Elite, top 1% of all Sportsbooks, Guaranteed safety & quality.B- to B+Good, minimal risk to players funds. Top 10% of all books.C- to C+Average to below average cust. service with some risk to players funds.D- to D+Poor, some risk to players funds. Poor customer service, etc.F to F+Caution, extreme risk to players funds. Possibility of a scam.F-Outright scam, book on brink of failure. No chance to recover funds.