Who needs a computer to find 6.c3? It's been played for years against the Fishing Pole.
But as Brian Wall, the main advocate of the Fishing Pole has shown, even against the "refutation", Black still has quite a few practical chances. Don't trust the engine's evaluations too much.
There was an aritcle in The Kenilworthian titled "The Fishing Hook/Fishing Pole Opening: RIP w/c goes 1 e4 e5 2 Nf3 Nc6 4 Bb5 Nf6 4 0-0 Ng4 (The Fishing Pole) 5 h3 h5.
One of the refutation (has a rating of +1.46 using "dual Opteron 240 with 2 GB ECC RAM and Deep Fritz 8 through level 19) is 6.c3 a6. Think there is a refutation to 6.c3 w/c is 6...Na5 and don't go about telling me about "A knight on the rim is dim" because to every rule, there is an exception.
The move clears up c6 for the cpawn and also prepares ...d5. So any comments on this?