1.c4 e5 2.d3 d6 What is this kind of opening?

There are 137 games in database on this site and no match for this variation...

Oops... mistake. 137 games without d6 (with it only 7 with huge difference win/lose for white)

It seems Black is playing a reversed Kings Indian against the Sicilian, down a tempo? 7 games tell you nothing about the viability of an opening.

Well 1.c4 e5 is called the reverse sicilian, a variation of the english opening. not sure about 2. d3 d6 because most master would play Nf3, Nc3 or g3...

2.d3 is an attempt to play a reversed Najdorf Sicilian.

In Explorer (if do the same steps for black) it is called Sicilian Defense: Modern Variations . Is this the same with Najdorf?

If u plan on going g2 you must play d3 here otherwise Black will play 2...d5 and if u take he takes with the queen and only way to block and void advancing pawn is f3 which screws your pawn structure

I don't know that you should try the Narjdorf Sicilian reversed - it's sharp enough with the white pieces, surrendering a tempo on top of that can't be good...

Depends on black's plan.?

If he follows up with Nd7, c6, Nfg6, Be7 etc ... then it's like an Old Indian.

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