A useful thought process or tool you should familiarize yourself with is placing opponents into categories, both for your current playing session as well as any future sessions against the same player. There are four broad categories of playing styles. By playing against an opponent and learning his or her tendencies, you can place them in a category and adjust your style when contesting a pot with them. I find that by putting names with categories it helps me remember how each opponent plays. Here is a list of different playing styles followed by a suggested name for each. Feel free to use your own names if they are easier for you to remember. One note of caution, just because a player has been included in one category in the past does not mean that he or she cannot be in a different one today. Players play differently at different times for many reasons. Some tight/aggressive players change to loose/aggressive when drinking while others will tighten up after a bad beat. Always take a little time to reevaluate players you have experience with to make sure they havent changed their style.
Tight/Aggressive Being this type of player should be your goal. This player doesnt play many hands, but when they do, they play very aggressively. The tight/aggressive player will often enter the pot with a raise and bet and raise until they win or are clearly beaten. Every time that a player bets or raises, it forces other players to make decisions and whenever a player must make a decision, he/she may make a mistake. The tight/aggressive player capitalizes on this by providing opportunities for his/her opponents to make these mistakes. The name I assign to these players is Solid. You must respect their bets and raises because they seldom enter a pot with a poor hand. Solid players maximize their intake with winning hands and minimize it with second best hands. When choosing a game, if I see too many solid players in it, I will usually find another game if one is available.
Loose/Aggressive The loose/aggressive player plays too many hands, usually raises and is very hard to bluff. When playing against them it is important to keep your starting hand requirements tight so that you are often in the hand with better cards than them. Most loose/aggressive players are trying to play the correct way, which is tight/aggressive, but simply play too many hands. In the long run, loose/aggressive players tend to be losing players because they play too many hands. The name I assign to the loose/aggressive player is Semi-Maniac. A player that is at the very outer edge of loose/aggressive is the Maniac. The Maniac plays many hands and always raises if they are in a hand. If you find yourself against a maniac, just sit back and wait for your very best starting hands. The maniac will pay you a very high price when you do have a great hand so you can afford to pass up the marginal ones.
Tight/Weak A tight/weak player has a solid understanding of starting hand requirements and follows them, but doesnt play Click here well after the flop. This player doesnt raise to protect their best hands, which often lets drawing hands catch-up without paying a high price. A tight/weak player much prefers checking and calling to see what is coming next. The tight/weak player may show a small profit in games full of poor players because of the proper starting hand selection, but will be eaten alive by solid players. I call the tight/weak players Sandstone, in reference to a weak rock.
Loose/Weak The loose/weak player plays too many hands, calls when he or she should raise or fold and almost always will pay you off on the river with second, third and often worse hands. I call these players Calling Stations. These are the players that many poker players call Fish. I know that the loose/weak player will always pay off my good hands and I often try to isolate him/her to take advantage of this.