behind the eight ball

I, ROBOTを読んでいます。
Powell brushed his mustache the wrong way, "So help me, Mike, another fool remark out of you, and I'll take away your rattle and teething ring."
"All right. You're the genius of the team. I'm just a poor sucker. Where do we stand?"
"Right behind the eight ball. I tried to work it backward through the 'finger,' and couldn't. So we've got to work it forward."
上の引用文中に出てきた "behind the eight ball" は慣用句の様です。辞書を見ます。
・Oxford English Dictionary: At a disadvantage.: don't let cash-flow crises put you behind the eight ball

・Collins Dictionary: in trouble or in a difficult situation: If a child doesn't get the basics in primary school they are way behind the eight ball.

・American Heritage Dictionary: In trouble or an awkward position, out of luck, as in His check bounced, leaving Jim behind the eight ball with his landlord. The term comes from pocket billiards or pool, where in certain games if the number eight ball is between the "cue ball" and "object ball" the player cannot make a straight shot.
ビリヤードにそんなルールのあるゲームがあるのですね。