That's right.If it's a skill-based game it can most likely be exploited.The game has to be based on luck,in order for it to be suitable for gambling.I used to play billiard games,when I was a kid.Now,I'm not interested in billiard sports.They are kinda boring for me.
Maybe some game developer could modify a version of 8-ball pool,which is based on luck,not skills.
The lines to the ball direction I think made this boring but taking that out must make the game fair which means both player will have to depend on their instinct to push the que to the target. That I think will be of skills.
Not the very exciting game to some people but to some its what make them stay up the night drinking beer, playing pools and betting. The locals have different kind of games when it comes to billiards which makes it more exciting.