In that case, you not only have to convince a judge that your case has merit, you also need to convince the lawyer.

They aren't going to work on contingency if they think your case is frivolous.

Agreed...and if they think there is a chance of winning they are going to work on the case. That seems obvious? I think you always need to convince a judge your case has merit, right? Or else they just 12b6 you or whatever the equivalent is...