It wasn't an attempt to be condescending but as you took it that way I offer my apologies.
It just seemed like you didn't know that in general athletes peak at age 27 and I was trying to be helpful. Obviously the way I responded allowed you to take it in a manner I didn't intend. I will work to do better in the future.
You should know with all honesty I have nothing but respect for your opinion and the value you bring to this board. I was one of the vocal ones for your return.
Apology accepted. Thanks for being so generous.
FWIW, here's what FO says about when football players begin to decline:
Football Outsiders annual said:
Running backs usually decline after age 28, tight ends after age 29, wide receivers after age 30, and quarterbacks after age 32.
This research was originally done by Doug Drinen (editor of pro-football-reference.com) in 2000. In recent years, a few players have had huge seasons above these general age limits, but the peak ages Drinen found a few years ago still apply to the majority of players.
As for “non-skill players,” research we did in 2007 for ESPN The Magazine suggested that defensive ends and defensive backs generally begin to decline after age 29, linebackers and offensive linemen after age 30, and defensive tackles after age 31. However, because we still have so few statistics to use to study linemen and defensive players, this research should not be considered definitive.
I agree that some athletes don't hit their peak until their second contract (the NBA is perverse in drafting 19 years olds and not knowing whether they'll be good for 5+ years). But I don't think that really answers the question posed by the OP. The "peak" for an NFL player is the intersection between their knowledge of the game (which increases over time) and the ability of their body (which decreases over time). I'd argue that football is unique in that the physical damage inflicted daily probably inhibits the overall outcome for most players.
Think of it as a leaky bucket — the player's body might be reaching peak performance by age 24 or 27, but that performance is continually being degraded by the sport they're playing.
Another way to think about it is look at BYU: you'd think their teams being 2+ years older would give them an advantage, but more talented athletes at the football factory schools are still able to outperform.
I think that teams generally have a good idea whether they have a dependable player during their rookie season. For example, I think it was clear very quickly that Haason Reddick was going to be a problematic draft choice, which is why, IIRC, he was playing in the 4th quarter of the 4th preseason game in his rookie year. Similar things happened with Bryant Johnson, Michael Floyd, Brandon Williams, etc.