A novelty. The knight is moving towards the c2  square from where it can support the central break with d2-d4.
1. c2c4  1... e7e5  2. g2g3  2... g8f6  3. f1g2  3... d7d5  4. c4d5  4... f6d5  5. g1f3  5... b8c6  6. e1g1  6... d5b6  7. b2b3  7... f8e7  8. c1b2  8... f7f6 