you don't really know what your team/payroll is going to look like 3-4 years into the future, and you don't know what your needs are going to be. if you figure a guy is worth 5 mil a year and he's going to be making 7-8 million towards the end of the contract because you backloaded it, that might end up hurting you more than you can anticipate. it's risky because you're sacrificing future payroll flexibility to get him cheaper at the beginning. i don't really care that much about backloaded contracts, but saying it's "always" a good idea is pretty silly. you never know exactly what your team/situation is going to look like 3-4 into the future.