For example, a player who only plays premium, high-quality hands, but does so in a relatively passive (read: non-raising) fashion, is said to be a Nit or a Rock. This person would be found in the lower left of the chart. When a player like this actually does raise, you need to look out; he or she probably has a very, very big hand:
Then there are those players who take the idea of playing more hands way too far, but also remain relatively passive. These players are called P-Fish (for "Passive") or Calling Stations. Players like this usually can't be bluffed very effectively, so the way to beat them is to take them to value town with your good hands, and quit when you miss:
If someone plays a lot of hands like a P-Fish, but does so in an aggressive manner, we would call him or her an A-Fish (Aggressive Fish). At the extreme upper right hand corner of this group would be the so-called Maniacs. Like P-Fish, bluffing doesn't work very well with these types of players. Betting for value is usually a good option against them, but just as frequently you an let them bet for you; i.e., you can play more passively against them with your big hands, letting them bet and raise, and you just call down. At some point in the hand, when they feel pot committed, you can start raising, too:
In the upper left hand corner of the VPIP vs. PFR chart are the players that are Level-1 and beginning Level-2 winners. This is what is usually taught to new students of the game as the basic formula for winning. TAG (Tight-AGressive) or Reg (for "Regulars") are the standard terms used for these players. They play a selective group of hands, and when they do so they play them very aggressively. This is the most common way to play winning poker, especially at the low limits. It can be a bit ABC and, therefore, exploitable. These players are also bluffable:
To the right of the TAGs on the chart are the so-called LAG (Loose-AGressive) players. Most professional players and solid Level-2 players adopt this style of play, as it's more profitable (and less exploitable) than plain ABC TAG play. On the other hand, it's much harder to play this style, and you have to be really good at reading your opponents' hand ranges. The variance can also be more extreme on your bankroll via a LAG approach:
But wait a minute. Didn't I write that there were seven types of players based on VPIP and PFR? Yep, I sure did. The seventh player is the true master of the game. This is the villain who actively changes his style of play to counter the way his opponents are playing. I call this type of player the Gear Change Specialist, or GCS, as they can effortlessly shift gears, moving their starting hand requirements between tight and loose, and their aggression between aggressive and passive to suit the current table dynamics. If they find themselves at a table of Nits? No problem, they adapt by playing somewhere between LAG and Maniac. Their opponents are Recreational players? Again, no problem, they adopt a basic TAG style. They're surrounded by Maniacs? Again, no problem; they simply tighten up their range and play more passively.
When players first start out, they almost always play a Nit or P-Fish style, with an emphasis on the latter. As they get better, they transition to Rec style, and eventually, TAG. Then they begin playing LAG, but frequently go back and forth between TAG and LAG as their bankroll gets beat-up and they learned the winning LAG style. And finally, at the higher stakes, winning players either stagnate at TAG or LAG style, or they truly advance their game by morphing into the GCS style. IMHO, this is where you should strive to play... and if and when you do master Gear Change Specialist style, you can exploit and attack the other six styles with ease.
All-in for now...