Papi did defy the bell curve by having his 4th best OPS year at age 40- hhis last year. He also had his best OPS+ year at age 36, 3rd best at 40, and 5th best at 37. His 7th best was at age 35.
His worst 3 OPS+ with the Sox, were ages 32, 33 and 34, which many, including myself felt were signs of continued decline.
His best, in order: 36, 31, 40, 30, 37, 29, 35, 28, 27, 38, 39
It's almost a perfect pattern of alternating pots 34 years with pre 31 years.
The normal peak years (maybe 28-30) were not his best.