Yeah, I would like to see players who were in the NHL at both 22 and 30 and see how the numbers look relative to each other. Also, would like context in terms of whether these players were in the dead puck era or not.
Lots of omitted contexts here
Some contexts that are missing:
1. Team record, just as Steven Stamkos how much easier it is to focus on offense once your team is out. Related to this is team gpg. Teams with a broader array of offensive weapons allow for increased individual offensive statistics due to both on team support and opponents having to focus on multiple threats, thus spreading their defense.
2. Health. Hard to measure, but some of those dips in Crosby's ppg are due to injuries that started mounting in the last few years. Same with Malkin. Look at Lindros and Selanne in chart 2, you see a direct correlation between health and lowered scoring. It may be that players are better younger because the NHL grind hasn't killed them yet. The Lindros drop in production is a direct result of the infamous "Stevens Fault Line" located along the NJD blueline in the late 1990s.
3. The numbers prove it, Joe Sackic was a freak of nature.
4. League gpg. Dead puck eras keep creeping back up on us. Crosby and Ovechkin's early numbers were products of run and gun, losing teams and tightly called games (as well as awe inspiring talent). When Jagr was moving into his late 20s at the height of the dead puck era, everybody's offense went down, not just his. To do this properly ppg has to be adjusted for deflation so that the points remain consistently comparable.
For me, team record is the most important one. Winning teams are, by their very nature, more defensive, play in more meaningful games, and, therefore, have less scoring opportunities later in the season that losing teams. Furthermore, those players have longer to recover in the offseason, building towards better individual statistics, but not necessarily more meaningful hockey (yes, this is another way of phrasing the "more complete player" argument, but I'm tying it into team dynamics which are an essential element of on ice hockey culture that can't be ignored, but isn't easily quantified). It's also hard to compare players on bad teams that let them run and gun with players on winning teams, and winning is more important. Let's face it, Jeff Carter just came off a season in which he was scoring goals at almost the same pace as he was in 08-09, but his assists were down. We all know that the Kings as a group couldn't pot a rebound in an empty net last year (heck, Kings fans could have legitimately worried about the entire team Patrick Stefanning the way that the offense was going at times), so age didn't slow him down.
Lots to chew on here. Thanks.
T2M
