100% BS unless he was talking about your stroke
Somepeople say you play with a heavy stick if they think you shoot to hard,light stick may mean dont shoot so hard in other words
The weight of your stick is what works for you 17 to 21oz its your choice -try a lighter stick just to be sure

I think he means Shot (heavy stick) or finesse (light)
finesse usually does win.

To rule the table you have to have practice, control of your stick, and self control. You know what practice is. Control of your stick, a hustler can go into a pool haul and use the house stick and win. He learns the shape of his stick and will spin it to control the direction the stick goes. If the stick is warped he will spin the stick so its curve seems straight. Self control is something all pool shooters must have. If you want to hustle make sure your are one who does not show he rules the table. The weight of the stick is what comforts you. Weight cannot be explained as a use of power, the power comes from you. Shoot with the stick you like. Don't let others play mind games on you.

What I think the guy is talking about, light or heavy stick, meaning weight, Common sense, I don't think there is a pool player, or a hustler that would use a crooked stick, Why should they?, You can eye a stick and see if it's straight, by putting your eye on the butt of the stick, and just look at it.
I like to use a 20 or 21 stick, usually a 21, and the shaft thick enough to just fit through that hole made by putting my middle
finger on top of the index, that is my choice. some people like light sticks, and thin shafts, I can't play with that combo.

OK, I am going to use extremes here so bare with me. Think of Sword fighting. in Braveheart, the swords were heavy as hell and they were good for very few moves with total control. In The Princess Bride the Swords were lighter and did close to the same job but were able to control a lot better, but would not do the same damage. Same goes with Pool cues, lighter the cue, the more control you can have over the cue ball, and will allow you to to more shots, ie. english, draw, follow, masse.

Cue weights are one of those controversial topics that pop up from time to time. The bottom line is the overall weight of the cue is secondary in importance to the condition of the tip and the straightness of the shaft. 20 oz. is a fine weight for a cue. I personally prefer a lighter cue, closer to 18 oz., and I have my reasons for it. I like to play straight pool and that game requires a delicate touch and often long innings at the table. A heavy cue might wear me out quicker. But that's just my take on it. Feel free to try out cues of varying weights, but ultimately stick with what you feel comfortable with. You migh find that you like a lighter cue or you might not notice any real difference at all. If it isn't broke, don't fix it. M.D.-BCA Instructor/Referee.