Something I started doing late last year was to create a spreadsheet with the names of the regulars and non-regulars in my games. The first column I have is a rating between 1 and 10 of what I think each players approximate skill level is. This allows me to quickly look at a table, add up my ratings and arrive at a number that tells me the skill level of a table. This is particularly useful when I'm playing 4 or 5 tables and have the choice of joining more tables. 4 or 5 is my capacity so I can quickly make a decision whether to stay in a game or drop the one I'm in and start a new one. Although I know most of the regulars in my games, there are a lot of semi-regular players where I recognize the names but can't remember how they play. You're probably thinking, why not look them up on PTR, wouldn't that be easier? One reason I don't do that is that it's against PokerStars T&C's to have PTR open while their client's open. The second reason is that PTR often doesn't tell the whole story. Players play NL and Limit which can skew win rates. Also, players play heads up and short-handed which skew win rates. It usually takes me about a hundred hands to get a very good idea of someone's skill level and I feel more confident in my assessment than looking at PTR.
In addition to my rating column, I have a long column with all of my notes. Specifically, areas where I think my opponent can be exploited. To give you an example of some of the things I look for:
- High fold big blind to steal%
- Low or High 3-bet %
- Preflop positions where my opponent is overagressive
- Whether my opponent checks back flops or not
- How showdown bound is my opponent - how bluffable is he
- High or low flop and turn check raise %'s
All of these things allow me to make adjustments against my opponents. For example, if somebody is checking back a lot of flops (by a lot I mean 10% or more), I'll adjust by 3-betting from the big blind preflop and capping when out of position and having been 3-bet.
A nice benefit of having everything in a spreadsheet is that I'm able to look at a table before I start playing and formulate a game plan in my head with regard to how I'll play against the table in general as well as the specific players. So for example, let's say there's a seat open with a player that has a low 3-bet% to the left of the seat and then a player with a high fold BB to steal % one or two seats after him. I'll make a mental note before sitting that I need to expand my stealing ranges. I find it a lot easier to do all this before I start playing rather than starting 4 tables at once and doing it on the fly.
In nearly all sports, the competitors know who they're up against and formulate a game plan prior to competing that seeks to exploit their opponent's weaknesses and maximize their strengths. Poker shouldn't be any different.