This phrase meaning "in a difficult situation" comes from the game of pool
Behind the eight ball (disambiguation), a phrase in English meaning 
"in a difficult situation", and the title of several films and songs; "2 Hookers and... [DOC] [TLE] Appendix:Glossary of pool, billiards and snooker - Wiktionary [PAR] In the UK, it usually means the game of English billiards.