Posted by Neil Paine on July 16, 2009
In response to Tuesday's post about Win Shares and aging, reader Jason J thought about whether or not today's improved equipment (including much better shoes), training methods, and dietary regiments made it easier for older players to stick around in the NBA for longer periods of time. It's a great question, because the success of recent players like John Stockton, Karl Malone, Michael Jordan, Reggie Miller, Dikembe Mutombo, etc. well into their forties makes you wonder if modern basketball technology is helping older players extend their careers longer than ever.
As a follow-up to that earlier post, today I'm going to look at what percentage of league Win Shares were credited to players at each age, both in the history of the NBA and broken up by decade (the fact that we're essentially through with the Oughts now is handy as well). Now you may be asking, how am I going to use Win Shares as the measuring stick, since we're unable to calculate that metric for seasons prior to 1978? Well, similar to the way we estimate PER and Statistical +/- for pre-1978 seasons, I also have estimated Win Shares for those who played in the pre-turnovers/offensive rebounds/blocks/steals era. For instance, here's Bill Russell:
Like I say, they're estimates at best, but I think it gives us a decent way to pull off studies like this, where a sample confined to players from 1978-2009 is just not big enough to be acceptable.
So, armed with this data, we can take a look at what % of league WS were attributed to players at each age. I'm also going to break things down by height; the median height in NBA history is 78 inches (that's 6'6" for the lazy), so I'll track the percentages by age for the subgroups of those 6'6" or shorter and those 6'7" or taller. Here's the breakdown for all of NBA history:
And here's a year-to-year graph of the phenomenon:
It looks like the uptick in productive older players was almost a one-time situation unique to the 1990s, which only seems to confirm that the stars who grew old in that era were a very special group of athletes. There were just so many superstars with staying power during that period -- Michael Jordan, Hakeem Olajuwon, David Robinson, Clyde Drexler, Charles Barkley, Karl Malone, Patrick Ewing, John Stockton... The list goes on and on. Truly, 'twas a great time to be a hoops fan.
Anyway, here's the data for just the "tall players":
And the "short players":
So, conclusions? Aside from essentially having more 30-somethings contributing from the start, there doesn't seem to be an appreciable difference between the shape of the graphs for bigger players and smaller ones. Both saw an increase in production from older players during the mid-to-late 1990s (the smaller players saw a distinct spike) as some of the aforementioned superstars neared the end of their illustrious careers. But during this decade, the 2000s, we have seen a return to the youth movement of the 1970s and early 80s, presumably fueled by the simultaneous retirement of greats like Jordan and the inclusion of young early-entry/prep-to-pro players like Kevin Garnett, Kobe Bryant, Tracy McGrady, & LeBron James. In fact, 2009 represented the greatest % of league Win Shares earned by the under-25 set in nearly 30 years, meaning that while today's older players don't stack up well vs. their 1990s counterparts, the future is nothing if not bright for the league as a whole because of an exceptional crop of youngsters on the rise.