Maniacs are a regular feature of online poker.
The maniac poker player is easily recognizable at the online poker table as the way he plays poker is completely out of sync with what other people consider poker playing to be.
The poker maniac gets involved with many hands, bets a lot, raises, make large size bets, reraise frequently. He creates panic at the table and radically changes the dynamics of the game.
Other players are scared to play most hands with him unless they have a monster. But monsters do not come by often, and meanwhile the maniac collects pots large and small and amasses a large stack.
The first thing to realize is that you can only make money with the maniac if you are willing to sustain a large increase in variance, i.e. in profit swings.
If you are used to play ABC poker in a tight-passive style and hate to gamble, then the best advice is to quit the table. There will always be another online poker table without a maniac and nobody is forcing you to play against him. This is one advantage of online poker compared to live poker, you can change table at the speed of light (almost).
If you stay, it is preferred to sit at the left of the maniac. If a maniac is sitting to your immediate left, this is a very disadvantageous position to be in, and most of the time it is better to leave. Otherwise the maniac can exert maximum pressure on your stack and wipe you out fast if you show some resistance.
Conversely if you sit to his left, you can play patiently and wait for premium hands. While waiting for good hole cards, focus on all his actions. There is no real need to study the other players at the table if there is a poker maniac, and you should employ all your energy to memorize the patterns of the maincs's playing style.
All maniacs are loose-aggressive-aggressive by definition, i.e. they have high VPIP/PFR/AF. They play a lot of hands pre flop (VPIP), raise a large portion of them (PFR) and raise often post flop (AF). But each maniac has his own style and by observing his habits and patterns, you can arm yourself with the tools that will enable you to set up a big trap at a later stage.
When you join a new table with a maniac of when a maniac joins your table, first play very cautiously because you want to analyze him and understand him before you confront him.
The key is to study the maniac and to take notes.
What is the size of his opening raise? Maniacs will vary the size of their preflop raise, usually depending on the quality of their hand. For example one maniac could raise 2 big blinds for a weak hand, 3 BB for any weak ace, 4 BB for medium pairs, 5 BB for strong aces, 7 BB for big pairs and 9 BB for aces.
Anytime there is a showdown, this enables you to compare his pre flop raise and his hole cards. Patterns can emerge very fast as he is involved with many hands.
Then you want to uncover his strategy at the flop. What is the size of his continuation bets? Does he tend to bluff his big hands or does he tend to slow play them? If the hand goes to the turn, does he make a second barrel bet, or does he shut down if he misses? And if he bets, how big is his bet?
There are sometimes some extraordinary maniacs who almost always bet or raise. But if their bet size at the turn seems to be irresolute, this is often sign of a weak hand. If he plays very fast, does he have a strong hand or is it a bluff?
Even though a maniac may win multi-stacks in one session and feel like the king of the universe, maniacs are losers in the long run. They are not as easy to beat as whales (very loose-passive players), but they should be a good source of profit, if you take the time to refine your strategy of how to play against poker maniacs.
Pokestars is the online poker room with the largest selection of table and the best opportunity to play against maniacs.