If he's good, his final year of arbitration will easily surpass $12m. Also, Theriot got $2.6m in his first year of arbitration, and that was by losing to the Cubs and taking their number. Castro will start at a higher level than you are assuming and make more every year. It was his first arbitration year, but he wasn't a Super-2 like Castro. Unless I'm misunderstanding the arbitration rules, which is very possible, then his $2.6 million for his 4th season would be compared to the $4 million I'm projecting for Castro in his fourth season. Jeter got 5M in for his 4th season 15 years before Castro would go to arbitration for his 4th season. And then 10M for his 5th season (again, obviously 15 years before Castro) You're way off.