Too Much Information
(Or, the other players really aren't stupid)
How you handle pre-flop raising can dramatically affect how much you win or lose at the game you're playing. If you are playing at a table where lots (if not all) of the people see the flop every single time and if you are follow the starting hand suggestions from this site, then you will almost always want to refrain from pre-flop raising. On the flip side of this, if you are holding something like
and call a bet in middle position and the pot is raised after you and everyone still calls then you shouldn't really be upset about that. If ten players call for $3 it's the value to you as if the bet is $6 or $12. The effect is only one of variance. If you flop your hand (which means a flush draw or two pair or better) you're going to continue--if you don't you're going to get out. It's that simple. If a heart flush appears on the board then you are usually going to win with the highest possible flush (!! a small percentage of the time you will lose to straight flushes, full houses and the like).
Because ultimately you are trying to flop something very strong to beat the ten active opponents (and something like a nut flush draw is very good because anyone who happens to have two of the other hearts is going to call (or raise) you all the way to the river). It's in your best interest to be able to see as many flops as possible with a suited ace. Which brings us to another point...
Raising Can Be Contagious
Take a typical 3-6 Hold 'em game where six or seven people are seeing the flop every single hand. Add to that game one tight and aggressive pre-flop raiser, let's say someone following Abdul Jalib's low limit advice (which is very good advice) and raising pre-flop with A-Q offsuit etc. You can usually count on a lot of action on the table if someone comes in and starts raising hands. The "gamblers" will start re-raising with any suited connector, and pretty soon you have a situation where pots are being capped before the flop.
One of the benefits of not raising a lot pre-flop is that, like a control rod in a nuclear reactor, you help to reduce the overall volatility of a low limit table. Those people more adept at playing higher limits might disagree with this, but try it and see.
Of course when this happens you'll only be playing hands from group 1 of our starting hand suggestions. You'll still have to be careful that you maintain at least 5-6 callers pre-flop. If the table starts tightening up and you are fighting against just a few other players then you need to adjust your strategy. Don't waste your money calling raises with T9 suited with only 2 other callers.
Raising Gives Information
If you raise pre-flop with only AQ, AK, AA, KK and QQ then you are giving your opponents a huge amount of information. Have you seen the following scenario at a low limit table? Player 1 raises pre-flop, Player 2 calls. Flop is garbage Player 1 bets, Player 2 calls, Turn is garbage--Player 1 bets, Player 2 calls. River is garbage, Player 1 bets, Player 2 raises, Player 1 calls and Player 2 shows off 2 pairs of garbage.
Player 2 was able to accurately put player 1 on a large pair (QQ, KK or AA) and used that information to extract an extra bet from them on the river when they picked up a 2 to go with their 7 (for example).
The bottom line is this: If you raise enough so that you add deception to your raises (sometimes raising random cards, or low suited connectors or small pocket pairs) you will often cause the rest of the table to increase the amount they raise on other hands making it too expensive to see the flop with may of the hands you would like to play, on the other hand if you only raise with a very small number of premium hands then you are giving out too much information.
If you follow our Starting Hand Selections, Avoid Raising Pre-Flop.
It's as simple as that. Use the information that others give you by their raises but avoid raising yourself.