When your opponent plays a different line against you but they lose anyways

On Saturday I played a 25|5 tournament. This game was from round two (if you guys want more I can give the other games). My opponent had been beaten by me in the past, in 25|5, by the alekhine. He played the exchange variation, but was unable to use a space advantage to his benefit and his weaknesses became all too apparent as my queen and knight invaded his position. (A similar case happened in the exchange alekhine in round five of this tournament - this time my queen and rook invaded to take second place!). 

So being a sensible person he decided to play the modern line, but of course, he enjoys his space, and is uncomfortable in a grind (otb I've seen him play opposite side castling French, and the nimzowitch Scandinavian so I know he's an opposite side castling attacker who's probably uncomfortable with a grind)... 

Here's our previous alekhine game if anyone cared:

@dababy this was for you because you seemed to be interested in alekhine

thank you B1Z : )

I've been looking at the main lines where the two knights end up on c6 and b6, I find them to be more coordinated than dxe5 if that makes sense

Nice game! I might play the Alekhine sometime...

the thing about alekhine is that outright attempts to blow it off the board usually make the game really sharp and fun

What do you think about castling queenside in the Alekhine? (as black)

bad... 

how does one punish it? I've played it a few times in blitz, and no ones punished me (when I haven't made a dumb blunder)

Can you show a game? Because Alekhine might transpose into caro or French structures and it really depends 

Here's a game I thought was rather nice

(yes I missed a mate in 1 xD)

In that specific position I think castling long was fine, because white couldn’t easily break with c3-c4 due to pressure on the d4 pawn, and he also wasn’t well placed to put pressure on the center (his knights got in the way). 

Generally, though, white should aim to counter blacks attack with very simple response: just centralize his pieces.

ah, okay