Why 2. c4, and not 2. Nf3, for beginners?

Why is it considered an inferior line for black ? (I'm asking because I may include it in my repertoire soon) 

According to my database, after 3...c6:

• 4. d4 is the most popular move, with a fairly good winning percentage. Subsequent play is similar to an Alapin Sicilian in reverse.
• 4. Nf3 d5 5. Bb3 seems equal. If 5. exd5, black can play ...e4 followed by ...cxd5 to regain the pawn.

Traditionally, from Fred Reinfeld on, beginners have been steered to 1. e4 e5 2. Nf3 for perfectly clear reasons. First of all, the direct attack on black's pawn forces him to respond (either by its defense with Nc6 or d3, f3 being invalid; or by counterattack with Nf6 or the risky f4). Thus black's options are limited. the Nf3 choice also fits the general principle of "knights before bishops" based on the fact that the knight's move is short, while the bishop's is long, so that knights need a head start toward engaging the enemy. Also, as has been mentioned by an earlier responder, Nf3 is almost always the natural square for the king knight, while the best square of the bishop depends on the further evolution of the opening: in various openings king bishops develop to c4, b5, d3, e2, even g2. Even in the most usual king's pawn openings, the choice of c4 or b5 after 2. ... Nc6 is a crucial determining point. Limiting your opponent's options while expanding your own is a good principle. But 2. Bc4 leaves Black a multitude of options while limiting White's own choice about the disposition of the important king bishop.

I think FM Andrew Karklins has made a bit of a career out of playing the Latvian.

Thanks a lot, guys!  Now, I'm even more confused. But I guess that's a good things.  It seems I have to decide for myself, since there's been arguments for both 2. Nf3 and 2. Nc4. At least I know one thing for sure: I'll be playing 1. e4 for now on. 

I don't think it matters if you play Bc4 or Nc3. What is important that you understand general principles of openings. You can play anything you want on move 2 b3, g3 that wouldn't change the evaluation of the position

RoseQ, people are different, and learn in different ways. For me, diving into the theory is absolutely necessary for learning. I'm sure you know more than chess than I do, but I know quite a bit about how I (and people in general) learn, having taught for many years. 

Having said that, I'm curious to know what you think is more important to learn.

I've dedicated about 50 hours weekly to chess. Only doing tactic puzzles for all these hours would not be the best use of my time. I work with the Tactics Trainer for 15 to 90 minutes daily.

Of course not. You must do playing and analysis of your own games as well. Tactics should be a fairly large part of your studying. Chess is decided by tactics and if you think you need to learn other things to make tactics in your games, you should probably be spending more time on tactics trainer.

Many coachest say more than half an hour of tactics daily is a waste of time. I think Rench or Pruess have said that 15 minutes a day is optimal. 

Oh, and by the way, I'm not "just" trying to memorize opening lines. Clearly, that would be kind of rather silly.

Tactics tactics tactics tactics tactics, as RainbowRising correctly points out.  It amuses me that players around my level (1800-1850) profess deep knowledge of opening theory.  Yes, there are book openings and "refuted" lines that are no longer played at the highest level, but there may be only a handful of players on the site who could beat one of the old masters who played these computer-refuted lines over the board.

Do not worry about opening lines too much.  If you can memorise every computer analysed line and its reported strength after deep analysis, then good for you.  Just remember though that one false move after the book opening finishes will make the previous 6-15 moves pointless.  Understand WHY you are making the moves, in general terms.  Don't learn by rote.  You will never learn chess this way.

My favourite opening is King's Gambit Accepted.  It has been largely refuted by Rybka.  I win against players 1800-1900 with it most of the time, so it can't be that dreadful.  Also, Judit Polgar and Nigel Short play it.  An opening is only 100% bad if you don't understand your objectives when playing it.

Oh, and Mikhail Tal would frequently play 1. h4 and 2. h5 in simuls against VERY strong players to demonstrate the folly of relying on rote opening preparation.  He was quite good, Mikhail Tal.

RainbowR..., I see you're rated 2523 in Bullet games, quite a bit less (2054) in Blitz, and even less in Standard (1785). And your rating in the Tactics Trainer is 2250. Why the significant rating drop from Bullet to Blitz to Standard? My guess is that you're damn good at tactics (as indicated by your TT rating), and this is a huge asset in Bullet games, less so in Blitz, and even less in Standard (and OTB) games. 

So, yes, I think tactics is (almost) everything in Bullet (and Blitz), but not in OTB games. My TT rating is 200 points below my Turn-Based rating, and my Blitz rating is 500 points below my Turn-Based rating. Why? Because my positional understand is my asset, while I need to work on my tactics (for sure). But not only on my tactics, since I do not aspire to become a Bullet master.

Good points, OnionT.... 

cigoL - excellent that you have good positional understanding (I don't, which is why I try not to make it as far as an endgame - death or glory!).  However, I see tactics in chess terms as being something you need to master before thinking about longer term strategy.  You can have the greatest positional sense yet be undone by losing a pawn to a vicious knight fork.

By the way - if you do want to practise tactics in a real game situation, I do recommend playing around with King's Gambit.  Every move counts, it's very sharp, and your king ends up fairly naked most of the time!  I am not a fantastic player by any means, but check out my King's Gambit games to see how double-edged games can be within just a few moves.

... Well, I'm not a huge fan of overly general principles anyway, but the advice almost invariably goes the other way around: develop the knights before bishops, since the knight tends to have a lower amount of attractive squares (The g1 knight for example goes to f3 very often, and even more so in a king pawn opening). Therefore, you're likely not to regret moving your knight to f3 (with exceptions of course!). On the other hand, the bishop has  many possible squares: the pinning square b5, the aggressive c4 square, d3, and the safe, cozy e2 square. If you move it out too early you may find that you actually want your bishop on a different square! Case in point: 2 Bc4: already, you can't play the ruy lopez.

As far as tactical study goes, as someone who has done thousands of tactics trainer puzzles, I still find that I recall more patterns when I am going over my own games with an engine. The quantity of tactics with this method is way less, but I actually remember the patterns because a missed tactic in one of your games connects to you on a personal level.

I don't find myself playing Be2 rarely in fact; even in the sicilian, it's a typical square for the bishop, simply because it connects the rooks without getting in the way (if a bishop on c4's pressure on f7 is not dangerous, it might get annoying to keep it on c4 because it's a little vulnerable (moves like ...Na5 or ...d5 can attack it often)). It is not immediately active, but it safeguards squares like f3 and often white doesn't mind it being passive for a while since at least he is connecting his rooks; the bishop will do something active later, when black's position is softer and white's better developed.

And yes, I would fit into that quiet player category, although usually white will put his bishop on d3 or g2 rather than e2.

Beginners should not even be thinking about openings at all. Openings are the last part of your game you should be investing time to develop. Knowing every opening in the world is not going to help you push a 1 point material advantage or a bishop pair advantage to a victory. Contrarily, having a dynamic understanding of core chess themes, such as positional play, tactics, and tempo is usuable at any time, including when the opponent uses a line or opening that you are unfamiliar with.

I suggest as a beginner you develop these concepts first. Then, work on your end-game theory. And once you are playing at a competitive level with all these tools in your arsenal, you can go pack and start to learn specific openings. Of course I don't even know how to play chess so maybe I'm just full of it.