Online adjustments for no-limit hold'em
Playing across a real table, players often get to observe each other closely for many hours at a stretch. Online adversaries are both anonymous and transitory.
Implications and needed adjustments
Successful online poker is, by its very nature, more card-based than people-based. This means you should do more trapping with your best hands, bluff less (especially against unknown opponents), and make fewer "moves." In other words, what works best in internet poker is less flash and more substance.
This generalization applies to all online poker games, including no-limit hold'em, although in certain instances you might intimidate a timid player on a tiny internet bankroll by putting in a substantial raise or check-raise with what's clearly an inferior hand. Just don't count on success - such ploys are likely to backfire online.
The problem with online aggression in cases where your cards don't warrant it, is that unlike in a physical no-limit game, it's much harder to figure out what funds a new player may have available for re-buys or what degree of risk tolerance he finds acceptable to call you down. And even if a new player is a rank newbie, you won't know that immediately since you can't see the way he or she handles chips or deals with other table matters. You'll simply have to play with that screen name long enough to observe the telltale showdowns that reveal experience level and playing style.
So we've established that you won't be able to evaluate opponents or make assumptions about their holdings on the basis of common visual or vocal tells, or by making inferences based on physical appearance. Just how can you make these determinations?
There are some internet timing tells, of course, but they're very tricky against experienced online players (and that's a subject for another time). Beyond that, my advice is to forget tells when playing no-limit hold'em in cyberspace unless you're playing at micro-limits where pauses or hasty action generally mean just what you think they do.
What about the chat box? Should you fear opponents who analyze previous action or criticize other players for getting lucky on the river? What about those who spout off odds and statistics? Or the ones who endlessly debate the way world-class players played key hands in the last major tournament?
In my experience, the best online players say virtually nothing at all in the chat box. They may type in an initial, "Hello everybody," when coming into a game, or inject a polite, "Nite, all," when departing. Otherwise, they have little to say. They do nothing to call attention to themselves and they usually play promptly. In fact, they do everything possible to be inconspicuous, fading into the virtual woodwork in the hope you'll forget they've played only two hands out of twenty. They're incredibly patient, like fishermen lying in wait for just the right moment to reel in a big one. And once they do, they may call it a day, moving on to yet another online fishing hole. They have no guilt pangs about this because they're there only to make money. And they know nobody will care how long they were there, whether it was for one hand or a thousand.
In many circles it's considered bad form to "take the money and run," after a good run of cards in a home game or traditional cardroom. Online, it's expected.
Online winners know this. They take full advantage of internet anonymity to move in and out of games as conditions dictate. They take the money and run.
To guard against these players, and to lay successful traps of your own with big hands, you must watch everything. I mean, as much as humanly possible, you must visually follow all the action and look at your computer screen whenever cards are in play. Is AuntJemima a calling station? Is she capable of slowplaying A-A or K-K? Will she call a raise with a baby pair? How will you know these things if you don't watch?
Naturally, the very first thing you should do when a new player arrives at the virtual table is check any notes you may have from previous play against that screen name. Believe it or not, most players at lower limits take no notes whatsoever. (I've done an informal survey.)
Unless you have notes on new players entering the game, you'll simply have nothing to go on but what you notice in the present action. And that's not a lot to go on. Some people think you can read a lot into an opponent's choice of screen name or stated place of residence, but from my experience, these details are more often misleading than not. At anything but micro-limits, they're probably designed to be as deceptive as possible. (By the way, if you don't take notes, you'll be at a tremendous disadvantage to those who do. You should start practicing the very first time you play no-limit hold'em or any other poker game online. Keep a book on every new opponent, and make sure to keep updating it - some players study and improve quickly.)
Before attempting a move such as a check-raise bluff or a significant raise with just a big draw, be very sure your notes indicate likelihood of success against that particular screen name. Otherwise, stay on the straight and narrow and let your cards dictate your play. When in doubt, don't bluff. Instead, wait to set a trap.
Up front, play only the very best starting hands. Remember that A-K is an underdog against any pair, including deuces, and be willing to relinquish it rather than risk your entire stack.
Although you might run a successful online bluff against someone who has been at the table long enough to see you consistently display quality cards at showdown, assume that any unknown new arrival may call you down with very little.
Remember that many players come to the virtual no-limit table with a minimum buy-in and therefore have only a small amount to lose by calling you down. Always note the stack size of anyone who comes into your no-limit game.
Finally, there's a third major difference I've observed between online and offline no-limit hold'em: many players, especially weaker players, play no-limit poker differently online than offline. They take more risks and call more frequently. They also treat money differently online than in physical games across tangible green felt.