I'm a little light on details but a lot of it has to do with the payroll tax under the new CBA (Collective Bargaining Agreement) between the owners and players. The Met's payroll this year is (so far) about $400 million so they will pay about $100 million in tax. The payroll tax is calculated based on the AAV of contracts. AAV stands for Average Annual Value so spreading the contract out a few extra years saves tax dollars. Evidently the math works.