I would be very hesitant to offer a 4, 5, or even 6 year deal. I would rather overpay on a 2 or 3 year deal that may or may not include a player option. Something like 2/66 with a player option for 3rd year, making it a 3/99 contract. I really like Darvish and would love getting him, but he is no spring chicken anymore.