Why Nc6???

I play 1.Nf3 but in almost every other game I am getting the seemingly bizarre 1...Nc6. I get that the idea is to play e5, but what is the plan after the obvious 2.d4? I've started transposing it to the London System to attempt to punish this weird move. People who are playing it, can you please explain what the thinking behind it is?

Nc6 in that position is not that great, but it is playable.
Some top grandmasters have played it, like Carlsen and Ivanchuk.
It often transposes into lines after 1.d4, d5 2.Bf4, Nc6 3.Nf3, but there are also some independent lines, like 1.Nf3, Nc6 2.d4, Nf6!? 3.d5, Nb8

It's the Chigorin Defense after black plays d5 in response to d4. Black aims to rapidly counter attack and undermine white's center with active piece play, instead of pawn play. It's a very active defense where black scores relatively well, though it's not that common. Morozevich regularly plays it, but lots of other top guys have played it at least on occasion - Ivanchuk, Short, Nakamura, Ponomariov, etc.

@OhNoMyPants so does this still count as a Chigorin without white playing c4?

#4 yes it does. playing in london style is acceptable, though.

however, i strongly believe that, at your level, most of your opponents are just improvising. i checked two of your Nf3 Nc6 games randomly, and it seems that you get some opening advantage just to throw it later

There's no "punishment" at all. For the record, after 1.Nf3 Nc6 2.e4 Black can play d5, e5 or even f5, not few strive for the Colorado gambit. And Chigorin is reasonable as well.

Colorado is trash.

lol, 1.Nf3 is weird also. How to punish it ? ^_^

@operaphantom 1.Nf3 is not weird as it prevents e5 from black, what do you mean? I explained in my post why Nc6 doesn't make sense to me