After 1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4, the most popular move (main line) is 4...Bf5. But former world champion Anatoly Karpov seems to like 4...Nd7. Since Karpov's style is "solidly positional, taking no risks but reacting mercilessly to any tiny errors made by his opponents," I am wondering if 4...Nd7 is generally considered more solid and less risky than 4...Bf5, at least by Karpov.

I am hoping that Anatoly Karpov can answer or comment on this question, but it does not seem realistic.