Chess Opening Theory/1. e4/1...c6/2. d4/2...d5/3. exd5/3...cxd5/4. c4

= Caro-Kann Panov-Botvinnik Attack= Nf6 is almost always played, with e6 having a particularly bad record.

Theory table
1.e4 c6 2.d4 d5 3.exd5 cxd5 4. c4