This sharking trick is a series of small distractions in the disguise of friendly sportsmanship or what could pass as normal playing chatter around the pool table. Nits are little nags about being careful about something important during play.
The once-in-a-while reminder in the course of a match could be considered mere courtesy. Multiple unsolicited inputs from your opponent are designed to disturb your intention to win and replace it with low-level irritation. Individually, nits are minor. When presented as a swarm of nits, they are major disturbances to your concentration.
If you are the type of person with low tolerances for interruptions, then you are an excellent victim of this shark. What begins as a minor irritant in the beginning of a match, after several games, they become major intrusions into your game analysis and planning. This is cumulative, so that as you enter the final drive to win the match, just hearing your opponent clear his throat ignites an internal battle to maintain self-control.
Here is a common pool nit, phrased as courteous kindness. "Wait a minute. You should be shooting the 5 ball, not the 11 ball." If he was correct, you are forced to give him credit for good sportsmanship. Not only was a serious playing error avoided (for which you beat yourself up), but you now “owe” him. But it is still a distraction, in spite of the apparent helpful assistance.
In an important competition, there is no reason for him to inform you about the potential foul. He just needs to keep quiet to receive the benefit of the penalty – ball in hand. But, as a sharking effort, he gets to "appear" to be full of good sportsmanship. And of course, his accepted intrusion gives him tacit permission to make comments later in the match.
If you don’t provide him an obvious opportunity to be “helpful”, it’s not difficult to manufacture a reason. His “correction” to a potential foul on your part doesn’t even have to be correct. Upon being told that he is wrong, he merely has to apologize –profusely, of course. Nonetheless, he has set the stage for his active participation during your turns at the table.
Regardless of the actual accuracy of his “helpful” behavior (and your internal feelings), you need to respond to his notifications. This means, you are forced to stop playing rhythm, turn to him and politely respond. Because of that redirection of your attention, you now have to restart your preparation routine. And while doing that, he is profusely apologizing for his attempt to be helpful.
After each nit, he keeps quiet for a turn or two. Just when you appear to be getting back into your playing rhythm, he suddenly intrudes again with the same sincere desire to prevent you from making a stupid mistake. Each nit is presented with innocent sincerity. Otherwise, any hint of intentional malice could result in a more dramatic confrontation.
Some examples of nits do not only concern what you are doing. It can also be used for the verification of some playing condition – always when you are at the table, such as, "You’re the solids, right?" or some request for clarification. Sometimes the phrase "Are you sure?" is included as soon as you have responded. An expert hustler can even incorporate a third confirmation by momentarily being distracted, seemingly forgetting the answer, and ask again for the answer. The more he works on you, the closer you get to a barely controlled boiling point. If he has successfully hustled you to win the match, you can receive a “final” nit, something like, "Thank you so much for letting me win."
You could handle this effort passively, letting it slide off by simply ignoring anything your opponent says (the deaf response). This tactic only works if you possess excessive patience or are mildly amused that he would seriously think that using such an obvious trick would affect your game.
If you like to become proactive, become the helpful nagger. Continuously provide good advice just as he gets ready to shoot, such as, “Don’t forget to chalk.” You can also use the “Make sure you stay down on the shot.” - which is a really good nag, guaranteed to help your opponent become a homicidal maniac. You can push this too strongly, so do be careful to smile abashedly when he glares in your direction.