Caro is the best opening for black?

The best moves technically are e5 and c5 (the Sicilian). These moves are best because they disallow white the strong centre with d4.

e5 is more solid as it gives black more symmetrical development and best chances to equalise.

c5 is more aggressive as it creates an imbalance and gives black the best counterattacking/winning chances.

c6 (the Caro Kann) and e6 (the French) are also very good and have their own system and tricks but they allow white to play d4 with a space advantage.

The French is more aggressive as black can still play c5 in 1 move and build up pressure on d4. Caro Kann is very solid as it allows black to develop the light square bishop, so they will have less weak pieces in their position. However, black will be much slower in pawn breaks, taking 2 moves to play c5.

So basically the Caro kann is more of a defensive opening and the Sicilian is an attacking one

Precisely. Also in the Sicilian, black is theoretically better in an endgame. One of the points of c5 is that it prevents d4 while preserving the central pawn mass, which can prove to be a structural advantage.

For example:

White has more rapid development but black has a central pawn majority and will later have counterplay down the semi-open c-file. The queen also has the open diagonal to play with which proves useful in many lines.

To give another variation as an example, white can try c3 (the Alapin) but black can force an IQP position which will also be better for black in an endgame, as the pawn is a structural weakness.

(Another downside of this is that white denies the c3 square from the knight, so black can also play it by not taking on d4 and developing more rapidly than white.)

For 1500-2000 chesscom imo the answer is yes. Probably along with certain sicilians.

The point is that in e5 as black you have to know too much for usual people. Same with sharp theoretical najdorf, dragon etc (but not with kan, for ex).

French requires very deep understanding.

All the other defences don't equalize, so are quite risky.

Btw, below 1500 e5 is the best. If both of the partners are out of the book on move 3 or 4 it is easier to stick to general principles here.

In all the other moves you deviate from the most straightforward play and have to understand why you do this.

I disagree with the above two comments because I think they are too dogmatic about what is/isn’t best.

We know with a pretty high degree of confidence in chess that there is a set of moves black can play which surely all draw with best play. That includes at least 1…e5, 1…c5, 1…e6 and 1…c6 possibly more than that.

So objectively I can’t tell you one is the best if, in a hypothetical “god vs god” matchup, a bunch of moves would lead to a draw if both sides played best moves. Therefore to my mind the question becomes more practical

I have seen young ambitious players climb to high ratings with all four of these moves. They have their differences though. The Sicilian is the most imbalanced, so maybe it gives black the most winning chances of the bunch while also being the riskiest. 1…e5 is probably what most of your opps at beginner and club level will be best-prepared against, although that doesn’t make it not a great option if you wanna go that path. French and Caro both totally playable, tend to lead to more closed type positions although not always. Plusses and minuses to each one

The only recommendation I’d give someone with a lot of confidence is this: don’t constantly switch between openings like I did back in the day. It wasted me a ton of time because each month I would find something new and cool to be obsessed with and by the next month I’d already move on. You’re best off focusing on making your existing repertoire good, rather than making a new good repertoire.

So what’s the best move for black on move one? Well maybe at the end of the day 1…e5 equalizes the easiest, relatively, but seeing as a bunch of moves are totally playable up to and beyond super GM level, the answer is the one you understand the best

The Caro can be played more dynamically as well, e.g. Tartakower vs classical, 3. ..c5 vs the advance, beyond the usual options.

I'd say pick 1. ..e5, as understanding of the open games is fundamental, not because their theory lines are more important than Caro's theory lines but because the Caro won't teach you a lot about the initiative, development and not as much about the center as the open games will.

It's no accident that in terms of historical evolution masters first understood well the open games ( ex-Staunton, who had a broader positional understanding ), and after that they moved to other systems. It's also no accident that most coaches recommend playing some open games before anything else.

The Caro is a great opening but you can look into it after a few years, when you have a solid grasp of the open games. It has a lot of lessons to give but in order of progression, understanding of development, initiative and the center typically come before light-square strategy and IQP positions. It's also very flexible ( it allows for having both sharp responses, dynamic positional and solid ) and contains a breadth of pawn structures.

Ultimately all major openings are completely fine, as others said whatever you choose, stick with it for a minimum of 2-3 years !

Mhm, there are a lot of coaches who believe all students should have to play 1. e4 e5 up to a certain level. Personally, I'm not one of them, I feel like I've seen too many young players have great results/make great progress who barely ever played either side of that position.

Tbh I've played everything at various points, but I guess I'd throw myself out as an example since I primarily played 1. d4 and primarily responded to 1. e4 with either e6 or c6 for most of my life, with a few stints of e5 and c5 thrown in there (as mentioned above, I jumped around a lot and it probably didn't help me). I definitely can't think of any evidence supporting that 1. e4 e5 study was central to my chess development, except insofar as it increased my general knowledge of chess.

That's just how I feel, I don't think there's anything special to those openings for someone's growth as a player, but I know there are people who feel differently. It's definitely still somewhat common for coaches to tell students to try to play e4 e5 positions as often as possible, so who knows

For me the two years I had spent on the open games was one of the biggest leaps in understanding and quality of play. This, second repertoire, was actually a simplification of my first repertoire following the advice my coach had given me then. Of course other factors could be at play, 2 years during teen years is a lot of time in personal development terms and also in chess terms as there was plenty of free time back then for team championships, tournaments etc, so lots of games played but I do feel the open games themselves where a factor.

It may not be the only route, I'm sure Fischer did fine without playing the open games as black as did Seirawan without playing the open games in general. But playing the open games for some time did pay dividends, while I can't say the same for all other openings I had played. It's been decades since then but e.g. I don't think the Dragon had helped me develop, nor did long prepared lines in other Sicilians. For quite some time I've settled for playing exclusively 1.d4 as White, as I exclusively play the Caro-Kann and clearly my memory of the openings I used to play a long time ago is sparse, but the middlegame lessons from playing the open games imo were worth their weight in gold. For me it was the period where I switched from all out pawn storms with opposite side casting in the Sicilian ( and generally overcomplicating without maintaining control of the position) to basically Steinitz, "Russian school" principles ( Dvoretsky, Shereshevsky etc ), and results changed accordingly. These days I'd find the task of maintaining an open games repertoire as too time intensive but reccomend them for development wholeheartedly.

The Caro in my opinion can be very tricky to play as Black. As White, you have a lot of aggressive and tricky options against it. All I did was play the Tal Variation which I learned from Gotham Chess and Black has a hard time beating it

You could play 4.dxc4 against 3...c5 but I found this very tricky move in 4.c4!? which has the best win rate compared to any other move on the Lichess Database. Against almost anything, yo follow up with 5.Nf3 and your opponent will usually play a bad move and as long as you know the ideas, easy win

When strictly talking about theory, and assuming both are strong titled players, the Sicilian is probably the best against 1. e4.

However, most people are not, and so the Sicilian is less effective.  This is because beginners are often taught how to play against the Sicilian or e5 first instead of something like the Caro-Kann. e4 players are likely to have seen the Sicilian more often and will therefore prepare a lot more against it. This means that a Sicilian player will have to prepare more as well.

The Caro-Kann does give up the center short-term, and Stockfish at a high depth evaluates the Sicilian as barely "better" than the Caro-Kann. Regardless, neither player is a computer, and so what the computer predicts for both players may not happen in game, especially at lower ratings.

Like all disappointing answers, the answer is that none is really better, choose your style and go with it.

This isn't true. From what I've seen, a lot of lower level players are totally unprepared against the Sicilian. The Bowdler Attack (2. Bc4) is extremely common for some reason, but it's just worse for white and black does extremely well against it.

How do you possibly arrive at the conclusion in your first sentence? That’s a massive claim. I think the furthest I’d be willing to go is that the Sicilian is included within the set of best moves, alongside at least one and probably three others. 

And furthermore, there’s just so much nuance within the question, like if we’re comparing just first moves only then what about different types of Sicilians, Petroff vs Berlin vs Open Spanish or whatever etc

And I also agree with what the previous poster said. I haven’t played the Sicilian in a long time, but I have many friends who do, and when I see games where random untitled club players have white, it’s not uncommon for 2. Nf3 3. d4 to be seemingly the entire extent of what white knows. Not to mention yeah you’ll get randos playing 2. Bc4 or trying to turn every position into the same default English Attack setup or whatever

So basically I can’t sign off on almost anything you said there lol, but hey I guess there’s a lot of room for differing opinions when we’re talking about such general questions 

Caro kan is passive defense.

This is flat out wrong, the Caro Kan can also be played dynamically and this is not even news for many years now, there is a ton of publications on how to do so. Even the more mainstream lines which are less dynamic, are not passive, Black certainly has counterplay.

The reputation of passivity comes from the very old plan with ..0-0-0 in the classical variation, even there, there are ideas to try..

The best opening for Black against e4 is either e5 or c5.
1... e5 is usually considered to be better for a draw, with prominent lines like the Classical Petrov, Berlin Ruy Lopez, Closed Morphy Ruy Lopez, and Giuoco Pianissimo.
1... c5 is usually considered to be better for a win, with prominent lines like the Accelerated Dragon, Poisoned Pawn Najdorf, Rossolimo Attack, and Taimanov.
1... c6 is my choice for the third best defense against e4, with prominent lines like the Tartakower, Advance Tal, and Breyer w/ Nf3.
1... e6 is my choice for the least viable ultra-viable defense against e4, with prominent lines like the Steinitz, Poisoned Pawn Winawer, and Grigoriev Chigorin MacCutcheon.

Besides the four above, there are a few lesser defenses against e4:
1... g6 is my choice for the fifth best, often transposing to other openings.
1... Nf6 is my choice for the sixth best, with a theory book that goes as deep as many lines in the defenses above.
1... Nc6 is my choice for the seventh best, held back only by White's ability to decline the defense entirely, after which the only viable transposition is to play 2... e5 and end up in a Scotch, Italian, or Ruy Lopez.

Anything below is hardly viable:
1... d6 is my choice for the eighth best, with far-too-critical mainlines, lackluster sidelines, and the one saving grace that is transpositions to other, better defenses. With White's co-operation, however, some of the less critical mainlines are quite pleasant for Black, and I would rank those right behind the Modern Defense.
1... d5 is my choice for the ninth best, as it allows White to nearly complete development at little to no cost.
1... b6 is my choice for the tenth best, as the opening gains Black nothing and allows White to play for incredible initiative.

Anything else isn't worth playing in the slightest.

Caro is not good because it tries to build a pawn chain and ignores development in the main line. 

It cannot be generalized like that.  The Dragon and the Taimanov are not the same at all.  Black goes all out in the Dragon, and in the Taimanov, he remains flexible and keeps tabs on White's attack.

To answer your original question, Black has 4 equally good responses to 1.e4, and which one is "best" varies from person to person depending on stylistic factors.

1...e5, 1...e6, 1...c5, and 1...c6 are stronger than the other 16 responses.  At that point, which is best depends on the individual.  A friend of mine and I are going to tournaments in late March in Atlanta and Mid-June in Las Vegas.  He has played the Sicilian (1...c5) since I have known him for almost 30 years.  I have played the French (1...e6) for just as long.  Come say, June, when we are in Vegas - if he faces 1.e4, almost certainly he will play 1...c5, and for me, I will play 1...e6.  As long as you play one of those four responses to 1.e4, it can last you a lifetime!