What is diminishing returns? The idea in basketball that if you put 2-3 players on the same team, who do the same things, they won't be as productive. A team full of Kobe Bryants or Tim Duncans would never make the playoffs, despite being individually great. They all do the same thing well, would get in each others way, and make everyone a worse player. I think this same phenomenon happened with the 2013 Lakers. Gasol and Dwight get in each others way, and though the trends are early, its beginning to look like Nash and Kobe are heading the say way.
The following is a table for Pau Gasol. It breaks down his FGA and FG% from 0-9 feet, as well as his overall TS%, for every year since he's been a Laker. The red column also shows the MPG by Bynum (07-12) and now Dwight (13).
Dwight/Bynum's MPG vs. Pau's FGA (0-9) = R2 = -.642
Dwight/Bynum's MPG vs. Pau Overall TS% = R2 = -.757
These confirm the trends, as we could say 64.2% of Pau's decrease in paint FGA had to do with Bynum/Howard's increased minutes. Likewise, 75.7% of Pau's decrease in TS% could be attributed to Dwight/Bynum's increase in MPG.
Pau Gasol has been declining for years, and while some credit has to be given to increased age and decreased confidence, a large amount must also be given to diminishing returns. As Bynum and now Dwight have stepped into larger roles, Gasol has been shunted to the side. As diminishing returns would predict however, pushing Gasol to the side isn't enough to make Bynum or Dwight play up to par.
We don't need graphs to tell us Dwight is having one of his worst seasons in terms of rebounding, field goal attempts, points, and shooting percentage. Although Bynum really came into his own during his final year as a Laker, he also put up a TS% of 59.4, the worst of his career since his sophomore year.
And no, the Gasol/Bynum tandem didn't win LA titles. Lamar Odom was a much larger part of those teams then Bynum, and he was a stretch forward, not a back to the basket bruiser. He allowed Gasol/Bynum the space they needed to be effective on the floor, and with him gone, the Lakers offense is/was a mess.
That's all folks. Diminishing returns is at work in the NBA, and its latest victim is the Los Angeles Lakers. This goes to show you can't just put players of talent on a team, and expect them to win. They have to complement each others skill set, and more or less "fit".