Actually can be spelled both ways :-)
What is the best defense to 1.d4?
The best one is the one that you perform best in.
Your post is useless. The OP's question was: "What is the best reply to 1.d4."
That's like someone asking "What's the nearest gas station?" and you respond with a useless answer like "The nearest gas station is the nearest gas station to you."
This is why hamsters (or any other animals) should not be allowed to comment in Internet forums.
If someone asks "What's the nearest gas station?" without bothering to mention where they are, then myeah, the question is frankly more useless than any answer can be :P
But fair enough, OP deserves a more constructive answer.
I'd say it depends a lot on what kind of game you like to play (or perhaps what kind of game your opponent does not). Are you interested in booking up and learning the theory, or just looking for a quick-and-easy way to get to a fairly even middle-game without too much fuss? Or maybe you'd rather just go ballistic and play a speculative sacrifice?
If you don't mind a bit of theory, then the Dutch is solid but still ambitious opening (that has the advantage of not being as common as Kings Indian/QG systems).
If you want a quick and easy way of getting to the middle-game without bothering to learn a lot of theory, you might want to look at hedgehog systems. They're slow, safe and solid - but you run the risk of getting squashed/squeezed to death if you don't know precisely when to strike out and unbalance the position.
If you want to just go mental, then there are loads and loads of fun to be had with the Charlick/Englund gambit after 1. d4 e5 but it might just be the least sound opening in the world ;)
I'm not acting! :P
I was actually more than a little serious. If someone wants an answer that helps them, the question needs to be a lot more specific. It's almost as generic as "how do I get better". ;)
1...d5 (this coming from a regular Kings Indian player). Learn the positional ideas first though, and you'll be fine.
chesslover1995, noone needs advice from a 1100 (no pun intended) If you are below 1500 FIDE (not chess.com) you should play 1...d5
BTW, in the budapest gambit you just take on c3 and play Qa3 =
This very instructional article seems to point to Nf6 and f5 as more challenging to 1.d4 than 1...d5. Agree/Disagree with it as you will .. but definitely worth a read.
http://www.correspondencechess.com/campbell/hard/h000331.htm
The answer is simple.
If you are under 2000, you should be learning opening concepts, not theory of complex openings. The Queen's Gambit Declined is the best for that purpose. It follows all general principals to the letter. Don't move pieces multiple times. Don't develop the Queen early. Get your share of the center. Maintain a strongpoint (that's 1...d5 in the QGD, 1...e5 in the Ruy Lopez, speak from Black's perspective in both). Etc etc.
Once you are over 2000, the best opening depends on your style of play. Positional players should prefer 1...e5, or e6- or Nc6-Sicilians (Kan, Taimanov, Accelerated Dragon,etc) or the Caro-Kann against 1.e4 and either 1...d5 Defenses (excluding the Semi-Slav) or Nimzo-Indian against 1.d4. Tactical players should prefer the French, Pirc/Modern/Pribyl systems, or d6-Sicilians (Najdorf, Dragon, Classical, etc) against 1.e4 and either the Semi-Slav or any defense where Black fianchettos his Dark-Squared Bishop (i.e. Grunfeld, KID, Modern Benoni, Leningrad Dutch, etc) against 1.d4
I said it's "simple", not "short and simple".
Data entry is a simple job, but it can take for ever to do, hence why they look for people with the ability to type 80 words a minute.
So Scottrf, I "+1" your statement, and send chesslover back to English class!
This very instructional article seems to point to Nf6 and f5 as more challenging to 1.d4 than 1...d5. Agree/Disagree with it as you will .. but definitely worth a read.
http://www.correspondencechess.com/campbell/hard/h000331.htm
quote from the article:"If Black wants to answer 1. d4 so as to preserve realistic play for the win, he needs to play 1…Nf6 and concede central space for the time being, or 1…f5, a dicey move that leaves Black's e-pawn weak."
Even if this is true for correspondece chess, it s clearly not true for normal chess. In candidates tournament we just saw 2800 rated players losing in rather simple and fully equal endgames with 1 or 2 minor pieces and few pawns. So you can be sure there is more than enough chance for the average player playing white after 1.d4 d5 to lose.
did bobby Fischer ever played d5 on first move?
Probably in his young days, but I never seen it, he always played the KID or Grunfeld, and even Benoni.
If he did, I would bet he was playing the Tarrasch Defence or the semi-slav
It's gruenfeld