I often don't agree with players regularly raising from the blinds in a limit cashgame. And I mean this specifically with regard to limit hold'em cashgames, as what I am about to explain cannot be applied to tournaments or pot/no limit cashgames. Raising from the blind positions in a limit cashgame is a dangerous move and should only be considered when playing against few opponents. I will explain my reasoning for this in the following article.
It encourages players to play their draws.
The first big problem that you have to face when raising from a blind position is that you give your opponents more reason to call your bet on the flop. Let's say you're playing KK in the big blind and four players called in front of you. If you don't raise in this situation, there will be five players seeing a flop. Therefore your opponents are getting pot odds of 6:1 to call your bet on the flop. If your opponent is playing a hand like A-9 against your K-K and the flop shows J-10-5, your opponent is a 7:1 underdog and should probably think about folding his hand if he wants to make profit in the long run.
Now let's assume we have the same situation as before, just that this time you decide to raise before the flop. It is unlikely that any of your opponents will fold their hand for that one extra bet before the flop. This will result in the potsize now being 10 bets instead of 5 as it was before. So if you now decide to bet on the flop, your opponent with A-9 now gets pot odds of 11:1. Suddenly you have made it very interesting for your opponent to stay in the hand, and all as a result of your preflop raise. Therefore, one of the main problems with raising from the big blind before the flop, is that you are practically inviting the other players to stay in the hand as the size of the pot gives them the correct odds to call.
The next problem you could encounter when raising from the blindposition is more of the psychological nature. Most of the players that called before the flop want to see a flop as cheaply as possible and will often be relieved when no player raises behind them. With you raising in the blindposition, you shatter their hopes of seeing a cheap flop. This again can result in some of the players seeking revenge for making them pay more to see a flop, which can lead to them calling you down to the river in the hope that you don't win the pot. Now with a hand like AA, KK or QQ, do you really want to have 5 players to see a river card?
Furthermore, players will respect your bet ON the flop a lot more if you didn't raise from the blinds before. If you play QQ and see a flop like J-8-7, of course you are going to bet in early position if no one raised before the flop. This is a sign of strength in the eyes of many players, and with a little bit of luck players on a draw will fold their draws on the flop or the turn. If you raise from the blind position before the flop, however, this bet might not get as much respect and players might call you down to the river.
Let's express this in percentage terms. If you play QQ against 4 other player holding A9, K10, 66 and J9, you have a 35% chance to win the pot if the flop shows J-8-7. If you force the players with A9 and 66 to fold their hands on the flop, your chances of winning increase to 51%. By raising before the flop you turn these two into frustrated players that aren't likely to fold their hands, and thereby reducing your chances of winning the hand.
The third and most obvious reason why you should not raise from the blind positions is that you will be out of position for the rest of the hand. How this will affect your play can be demonstrated with the following example.
You have KK and you raise from the blind position. The flop shows . You bet and the player behind you calls. Does your opponent have an ace or is he on a flush draw? You have absolutely no idea. Whatever he is holding, it is going to be very hard for you in your position to bet on the turn. If the turn card is rubbish then you want to check, but if your opponent is on a flush draw or hit middle pair, you just gave him a free card. Additionally you are giving him the option to semi-bluff you (a bluff with hidden outs). And if they semi-bluff on the turn, then they are likely to keep doing so in order to buy the pot. How good does it feel to call bets on the turn and river when you're holding KK and there's an ace on the board?
In this previous example I would not raise from the blind position. If that flop hits then I'll bet. If I get called I will check the turn. By playing my hand like this my opponent will often put me on an ace with a low kicker. For this reason he will usually assume that I will call a turn and river bet with my ace, which reduces the possibility of him bluffing on the turn. It has now cost me two small bets (1 before and 1 after the flop) to find out if my hand has a good chance of winning. If you raise before the flop it has already cost you 2 small bets before the flop, plus 1 after the flop, so 3 bets in total, and by the end you still don't have any useful information regarding the hand of your opponent.
You give your hand away.
I believe that by raising in the blind position before the flop, you give away the strength of your hand. So as a result, you get to see a flop out of position, with every player in the hand having a pretty good idea about what cards you are holding. Not a great situation in a poker game.
When should you raise from the blindposition?
My advice is that you can raise from the blindposition if you're dealing with few opponents. If you're playing heads-up before the flop you should raise with every strong hand, so also with AJ's and AQ's. If there are more than 3 players in the pot I prefer the check/call strategy in the blinds and then bet out on the flop.
Another situation where you should raise from the blind position is when 2 players called and a third player raises in late position. I usually re-raise in this situation to try and get the two callers out of the pot. If they do end up calling I would check/raise the IR in late position if they bet out on the flop. If there are more than 2 players between you and the raiser I would prefer to call his raise before the flop and to check/raise the raiser in late position on the flop. This is a very effective way of reducing the number of players in a pot.
One big advantage of just calling from the blind position with a strong hand is the hidden strength. Nobody knows what you're playing. They usually assume that you have a weak hand on the blind. I can remember a really big pot I won once with AA. Five layers called before the flop and I didn't raise from the big blind. The flop showed A-2-9. I bet and two players called. The turn card was a 2. I bet, one player raised, I re-raised, he re-raised, I re-raised and he called. After he called my bet on the river he asked me "what's your kicker with that deuce?" He was astonished when I showed my cards and he asked "why didn't you raise before the flop?" he had hit a pair of 2's on the flop and hit trips on the turn and he was sure I didn't have a full house with aces. That's why he gave me so much action. If I would have raised preflop and re-raised on the turn he would have probably figured out that I was holding aces and slowed it down.
There is one more little advantage when you don't raise a strong hand from the blind. The players paying attention will realize that you don't always raise with your strong hands before the flop. As a result, they might put you on a strong hand the next time you limp into a pot and might give you free cards on the flop or turn. This works out very nicely for you when playing a hand like low suited connectors.