(This is today's bit of advice from the book Safety Toolbox.)
With prior competitive experience against an opponent, you possess a wealth of knowledge that can be used in the current match. Previous playing experiences should provide a list of what defensive measures worked and which didn't. You will also know the kinds of shooting opportunities he likes. Don't forget the lessons learned from situations that you gave him by accident.
It is important to avoid becoming complacent. As soon as you stop considering him worthy of your best efforts, you begin relaxing your standards. When you do that, there are a lot of negative consequences. Just one of them is that you start losing games that should have been won.
BPI (balls per inning) average
This is the average number of balls a player pockets per inning, averaged over several games in a match. Some innings have a count of zero (a tough shot that was missed) up through a good run made because of an easy layout. It is similar to baseball’s batting average stats. Knowing your opponent’s pocketing skills expressed as an assigned BPI is important for setting certain traps.
The more skilled an opponent is the higher the BPI – and conversely, the less skilled he is, the lower his BPI number. Watching him play one or two games should give you enough information to assign a working number (for example, 2.5 BPI average). Over-estimate slightly to be on the safe side and give him a 3.0 BPI average.
In the complex world of table billiards, perfection rarely is achieved. There is always something to be corrected, reduced, minimized, modified, changed, fixed, etc.
Every player from the casual bar-banger to the professional lives in a state of imperfection. Knowing this, always identify those playing routines and unconscious behaviors that are his bad habits.
He may have a blind spot about his weaknesses – just about every player does. There are always layouts where he believes he is in a good position, but actually is in deep trouble. Often you can see this coming and predict the results.
Learning your opponent’s bad habits require close scrutiny of everything he does from how he waits his turn, his emotional stability, and all of his playing routines. Don't forget to analyze how he selects his shots. There is always something that he does that indicates weaknesses to be utilized in your plans.
The best time to gather information is when your opponent is in competition with another individual of similar skills. Since you are not involved, you are able to devote all of your analysis skills.
Observing matches gives you double-benefits. You learn about your upcoming opponent plus the guy he’s playing against. If that option is not available, observe him as he warms up. From this, create a general set of working guidelines. Refine these as you gain more details.
While competing, continue your scrutiny. He may have fixed something – meaning that a previous assumption is no longer valid. Or, he may have relaxed his standards and allowed previously conquered bad habits to reassert themselves.
Assemble a mental list of observed imperfections and careless table manners. This will give you the clues and indicators that will help you configure your strategies and tactics. Knowing what he can and can't do will help you win.