Although Mark and Bryon have made money before from hustling at pool at Charlie's place, it is clear in the opening chapter that they are not going to be able to hustle anybody that night, as there is nobody for them to hustle. Charlie says this to Mark after he sees him "scouting out" the other two guys in his bar, and Mark agrees with Charlie's assessment: this night there is going to be no hustling. Charlie says that this is actually a good thing:
You guys are going to get in real bad trouble one of these days. Some guy's going to get hacked off when he finds out what you're doin', and you're gonna get a pool stick rammed down your throats.
Note how this serves to introduce an element of danger into the narrative at this early stage in the text, suggesting that Mark and Bryon's tricks will catch up with them. Mark and Bryon therefore don't hustle anybody in the opening chapter of this book, although they have managed to successfully hustle before.