It's not controversial, it's stating an absolute as fact. Again, there's no way of knowing. Over a long enough timeline, yes, it is very likely a player will get worse as he gets older. It's almost a given that 97 year old Braun will be worse than 32 year old Braun. But in the short-term, it is unreasonable to suggest that a 36 year old will definitely, assuredly be worse than a 32 year old. Also, what exactly is "worse" - what if he is cumulatively more productive in the next 5 years than he was in the previous 5 years? Is he still worse if he tails off at the end? Edit: To clarify the last sentance... Braun's fWAR the previous 5 seasons: 2.8, .7, 1.6, 7.3, 7.1 = 19.5 WAR, or 3.9 WAR per year. What if his next five seasons turned out to be: 6.0, 5.6, 4.5, 2.5, 1? = 19.6 WAR, or 3.92 WAR per year. Not completely out of the realm of possibility, especially with him moving back to left field. Or if traded to an AL team/the NL adopts it, DH. Which is worse? Or, if you prefer, he has a 2.8 fWAR last year. Same hypothetical next five seasons as above. Is he worse just because he's worse the last two years? Or isn't it a net gain for the Brewers (or whichever club he's playing for)?