You need to learn how to analyze the game and then and only then learn to do it quicker. If you are a beginner be careful of playing blitz - it can spoil your skill. Later on, it has benefits.

I suggest visiting this site: www.danheisman.com  NM Dan Heisman has a strong opinion on the development of chess skills and  blitz chess. You can also find many good free articles written by Dan Heisman at www.chesscafe.com . Click on the Novice Nook link on the homepage.

"4. Roadblock: Not playing enough very slow games
I cut my teeth playing games at about 48 moves in two hours (48/2);
however today’s players, especially internet denizens, think that 30 minutes is a really long game! Unfortunately, that is a fairly quick speed where it is difficult to either carry lessons forward from one game to the next or to play “Real Chess” on each move. Many get hooked on the convenience and lure of on-line speed games.

A player who plays 100 games at G/90 or slower during the year is
likely to improve at a much greater rate than one who plays half of that or almost all games at 30 minutes or faster."  -  Dan Heisman

I suck at chess, but it would be interesting to do a study on this subject.  If you played blitz games, you will expose yourself to many more chess patterns, tactics, and openings though your depth of thinking will necessarily be limited by the time constraints.  

The trade-off between quantity and quality is essentially your question Eo___(hope I didn't add too many "___"'s to your name). 

Take learning a musical instrument for instance.  Typically one learns proper technique then strives to do it faster without sacrificing accuracy as ninevah suggests. 

However, when should one move from practicing one musical piece to the next slightly more difficult piece?  Only when the first piece is perfected?  When the first piece is 95% perfected?  70% perfected? and so on. 

There is a concept of diminishing returns in learning.  For instance, a beginner who tries to analyze an Anand-Kramnik position for 2 hours a day for 2 weeks will likely get crushed by another beginner who practices tactics in that same time frame. 

Likewise in higher education, perfection is rarely the standard to which one must live up to before moving on to the more advanced stage (e.g. you don't need to get 100% on every math test to pass the course, or even to get a high honors marking).  

I think it comes down to "the enemy of good is perfect".  Therefore, blitz is good.

At my level I consider that a 20 minute game will bring out my full potential as a player. I haven't the focus talent or ability to benifit from more time per game than this. I feel however that while this is true, anything less than this and my quality of chess diminishes drastically. I do not feel that playing fast time controls (any less than 10 minutes per game) can help you chess in any way.

For beginners who are weak in openings, tactics, strategy, and end games...blitz games do not allow for finding anything nearing a "best" move...by it's nature...you can "push wood" and win blitz games...once you push the fastest.

When we have establised some understanding of chess(not perfection), we may want to challenge our selves in blitz...but as a frequent menu, it will do more harm than good. The secret though is moderation...understand that it is not a vehicle to really teach you the game...but just an appitiser.

As the student of the best student of Dan Heisman (Dan Yeager, my best friend and mentor), it feels odd to have Yeags recommend blitz to me highly for pattern recognition. Maybe it's because he made me play slow time control games that I thought were monotonous, until I was "ready" to play Blitz. Once the foundations are laid, pattern recognition and tactics can be reinforced in blitz; I think it's best to play it second, but it is not detrimental if you play in slow games frequently to keep your search for the "best move" fresh.

Unfortunately, bar chess club days, I play in mostly short time controls! Maybe that attributes to my bad ratings... I've only been playing for a year though, so I'm by no means an expert.

I can see what many of you are saying, but in spite of that, I have to say that my modest improvement was from doing multiple thousands of tactical problems fairly quickly (kind of like blitz).  The reason was because of pattern recognition.  I read tactics books that tried to teach me how to recognize tactics, but they were useless...only repetitive practice helped because I could see more often in many different positions the mistakes I made and why they were mistakes and absorbed those patterns more effectively. 

My hypothesis then is that if you play blitz consistently for a long time, you will subconsciously (and more immediately) see the refutations of your faulty analysis which will help you learn more, learn quicker, and analyze quicker without needing a long time to do so, which I think Eo___ was hinting at. 

Still, I don't think blitz breeds that kind of subtle positional understanding that a long time control game does. Gambits and dubious play are frequent in blitz, where a regular, long time control game will provide you with something to stare at and break down. It is not just tactics that wins games. As Fischer once said: "Tactics flow from a superior position." Until you sit down and really analyze some games that both players put a great deal of time into, attaining that superior position may be a difficult thing indeed.

I was started on an hour per player with thirty second increments per move. If it weren't my good friend Dan sitting across from me, no doubt I would have ran screaming out of the room after my brain melted. Yet, it has made me a better player, I feel, than playing hours and hours of blitz has.

Blitz ruins your chess.

 The problem is that when you lose a blitz and analize it and find what went wrong ti doesn't help because just as you did not have the time to see what went wrong this time you probably wont have time next time either. Also playing blitz makes you ill-at-ease at the chess board. It dulls your accute sense of piece trade technique and does a number on your endgame. To top it all off some say that it helps your calculation, but in fact I believe it damages it making you play more by intuition and almost no calculation or evaluation and to play good chess you need all three. In conclusion blitz creates too many bad habits and gives to few good ones to be a valuable learning tool for a serious player. 

Yes, but superior positions can only be obtained after tactical threats/refutations are thoroughly understood and avoided. 

My point is that blitz can help you analyze the tactics of positions faster, which will only help positional analysis.  When you can eliminate those threats quickly without having to use as much clock as your opponent, you can address more subtle positional/strategic concepts sooner and more accurately. 

For instance, if I am capable of fairly quickly recognizing an x-move tactical threat, I can come up with a strategic "plan" that is perhaps x+1 moves deep, and if my opponent's next move happens to refute this, I can come up with a new plan by first recognizing the more immediate new threats to my position. 

This give and take is what makes positional games exciting for those that can follow the multi-move threats that are there on one move but refuted on the next, with new plans being constantly made, destroyed, etc.  

They're bad for developing skills because they don't develop skills at all.  They may help with your time management skills if you frequently get into time trouble but they don't develop your chess skill.

Long games, where you really challenge your decisions each move, make you better at playing chess.  Fast games are about finding OK moves quickly, that's it.

Yes, I know what Dan Heisman says. The problem however is not stated correctly. If you can't go to a chess club, the choice is between playing blitz or not playing at all. Almost nobody plays long games on the internet. Neither here, nor on ICC or elsewhere. I remember how I was waiting even more than 15 minutes for an opponent to play an extremely long game of 15 minutes per side. Why people don't play serious games on the internet? Cheating, of course.

I disagree, costelus. There are plenty of slow games available here. If two/three days per move is not a slow game then I am not sure what qualifies as slow!

I spend many hours together with my wife each day. I love her dearly, but she does not love chess. Why can't a woman be more like a man?  Many of those hours spent together playing long chess............

A beginner studying tactics will eventually learn what to do and not do when capturing pieces, and learn some "tricks" along the way (forks, skewers, pins, etc.).  This same person will probably be out of their element when they play someone that doesn't give them the opportunity to use these tactics--forcing the player to come up with a solid strategy to make any progress on the "attack".  (Or they'll revert to trying to trade everything off the board in the hopes of getting a tactic worked in there along the way.)  In the same manner, a beginner that devotes all their time to the opening may have great success in achieving a solid position to play the rest of the game from, but struggle at first with pressing the advantage once he or she moves past their "familiar moves".  In fact, they may face an opening they don't know and try to use moves that are "comfortable" against it to horrible effect.

I would agree with those that favor a longer time control vs. faster games.  It gives you more time to exercise your brain and help your ability to think your way through a situation, formulate a strategy, and calculate whether your ideas are sound positionally and tacticly or not.  Playing a lot of quicker games may be beneficial for a short time as a beginner, during the "trial and error" phase where the "youthful" ideas of playing things such as 1.) a4 followed by Rook to a3 (or trying to develop your queen first) are worked out of their system--to be replaced by new ideas that may or may not be much better.  Making blitz the core of a player's chess experience will eventually limit more than help the player's growth.  I also think there's something to the notion that playing longer time controls helps you develop the patience required to think through a standard game.  There's a real danger of falling into the mindset of, "I'm used to making a move within X number of seconds.  I won't worry about using all this extra time unless I get into a bind."  You put yourself at a disadvantage against your opponent if they know what to do with their time (and yours) and you don't. 

Blitz is fun, and for some, all they're looking for is that quick "battle of wits".  That's fine, but I think anyone who is wanting to learn how to play well would be doing themselves a favor by not limiting their experience to playing just blitz.

blitz is good for the old noggin, dont let anyone tell ya otherwise

Before my recent decade long vacation from chess, I used to be an occasional player in the local monthly tournament -- one game every Wednesday night for four consecutive weeks, 90 minute sudden-death. I also played recreationally with friends once or twice a month, and since some of them also on rare occasions played the local tournament, we adopted the G/90 format.

Then one friend and I, both self-employed, decided to play a weekly lunchtime game, G/30. It ruined my serious game. When positions required thought and analysis, I became too conscious of the time, and before coming to a conclusion based on analysis, I'd revert to instinct and play a "let's see what happens if I do this" move, often with disasterous results.

Now, had I played 10,000 blitz games,maybe I'd have known how to get out of that problem. Of course, had I analysed a similar position in 2 or 3 serious games, I'd have avoided it in the first place.

Blitz is instinct, not analysis. It may help you practice what you already know, but it's not good for efficiently learning something new. It can bring about bad habits at least as easily as it can bestow benefits. It may make you lazy and success may bring about overconfidence.

If your goal is to become better at blitz, play blitz. If your goal is to become better at chess, play long.

And if more people would TRY to find long games on the Internet, eventually, those interested would come and play. Don't give up after looking one time for five minutes. Keep coming back. Maybe most aren't interested in long games, but there are a lot of people in this world, and it only takes a few.

Good .You learn to think faster.

Your brains are getting well trained by this kind of chess playing. 

However the player who's specialized in some openings have a advance qua time.

Anyway it keeps your blood running in the head department and concentration

will be trained. Napoleon had also to make quick decisions  during his battles

but he failed at the last one (where he found his Waterloo)!