What is the best response to 1...d5

After 1.e4 d5 2.exd5 Nf6, I like 3.d4.

If Black plays 3...Nxd5, then Nf3 Be2 0-0 and c4, a bit like the Alekhine. Black also sometimes tries 3...Bg4, but I believe that is good for white after 4.f3 Bf5 5.g4 Bg6 6.c4.

i have a good question for you,after nf6 what if white blacks Bb5+?black has to play a move to block to queen and then white plays Bc4,is there a refuation for this line???

 A carokann devotee playing the Traxler ?!  LOL  When donkeys fly.......

 Eh?? You don't lose any tempi in the Scandinavian! Take a look at the position after 3... Qa5. White has one piece developed. So does black. It is white to move, so he is a half-tempo ahead. The same as in the starting position.

Exactly. People forget that by exd5 Qxd5, black also "wins a tempo".

I feel a bit ashamed of writing the above, because I believe Nimzowitsch's theory of tempi is absurd. What matters is the position, not how many tempi it took to reach it.

 Of course the position is the most relevant, but the number of tempi you used to get your pieces into their positions decides how many tempi your opponent has had to do the same... and so it is important to develop quickly, to stop your opponent reaching a developmental advantage. This is the theory of 'tempo'. Each player takes the same number of tempi to reach any position (assuming whites move) because moves alternate! It's how you use the tempi that is crucial.

Sure, but there are so many positions where one side has lost many tempi and is still better, the idea is useless. Watson refuted the whole concept pretty decisively in Secrets of Modern Chess Strategy.

 That, surely, depends on how you define tempi. For example, if I have a useless knight on a3 that is doing nothing, I would not count that as development. Some people would. My count of tempi relates to positional advantage, and so I have never come across a position where a side with more development (in MY system) is worse. (Assuming material equality.)

Yes yes, tempi schmempi.

Anyhoo, I'm surprised no-one has mentioned the 3.Nf3 line. It looks pretty juicy to me and leaves your c pawn free to go to c4.

I've started playing 2.exd5 again only because of 3.Nf3.

In an open game, development is almost always an advantage. In closed posistions, that really isn't so important, as it takes many moves to do things anyways and piece activity is too limited for it to be so important. The only thing that usually compensates for development in an open game is material, but then again people sacrifice material to get a lead in development.

I would think that the best response to 1...d5 is 2.cxd5!

For those who may have never heard of the Traxler, here is pretty good overview:

http://www.chessgames.com/perl/chesscollection?cid=1008357

I entered into a thematic tournament here surrounding the Two Knights Defense with the explicit hope of playing the Traxler with all of my black games. Alas, only one of my opponents was obliging. What's interesting is that one of my other opponents apparently played "half of the time 4.Ng5 and the other half 4.d4". And I got unlucky.

Not a bad idea.

I fear that my single Wilkes-Barre book is outdated though, compared to, well, really compared to anything.

The Traxler is very risky from the black perspective.  If you do not know the exact lines you will be destroyed in under 20 moves.  My favorite move after

1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 Bc5 is

5.Nxf7

This is extremely difficult to face over the board.  My theory is very deep in this variation.  What would be your response to Nxp?

Well I don't understand how black is justified in playing ...Bxf2+ without the knight on g4. If this was true, then couldn't white just play Bxf7+ instead of Ng5? I haven't actually looked deeper than that though. Nxf7 looks very natural by the way.

It's the other way around -- much more difficult to face as white. A black player will almost always be better prepared than his counterpart. If white doesn't know much theory he will lose in <20 moves. And if he has never experienced the opening before, he will be incredulous that it's even playable.

But if white knows the theory it's probably bad for black even if he knows it.

Why would white possibly know the theory?

I can tell you that it would be a fun opening to be an expert in. Along with the Halloween and the Cochrane.

You're assuming white doesn't know the theory? Well maybe not until he played against it but if someone loses to it once they will probably want to figure out how to beat it like most suprise weapons. According to this database, black wins alot which suprises me. I mean if someone spent as much effort on beating stuff like the traxler instead of using it it wouldn't be so dangerous. But if you don't know it the problems are often too complex to face over the board. I will give it that, that the opening is not easily refuted or just worse for black, but it probably can be done with effort.