The Turnover Era in BoxScoreGeeks

For advanced analytics fans, 1977 was an important year in the NBA. In 1977-78, the NBA started tracking individual turnovers in the boxscore. So when I began updating the BoxScore Geeks database to add historical data, it made sense to start with the 1977-78 season.

Image from FatShawnKemp.

One of the reasons I started this project is to have some data to make some cool historical comparisons. With that in mind, I've added a page with the top 50 seasons of all time. The top ten are interesting, and the page itself stands out for a couple of reasons:

Dennis Rodman DET 1991-92 3.5 82 3301 0.564 .433 29.8 10.4 11.6 22.2 2.8
Charles Barkley PHI 1989-90 3.6 79 3082 0.532 .422 27.1 10.0 31.0 14.2 4.8
Michael Jordan CHI 1988-89 1.9 81 3255 0.457 .390 26.5 9.1 38.8 9.6 9.6
Magic Johnson LAL 1982-83 1.0 79 2907 0.490 .413 25.0 9.8 21.9 11.3 13.7
Magic Johnson LAL 1981-82 1.0 78 2991 0.488 .400 25.0 9.4 23.2 12.1 11.9
Charles Barkley PHI 1988-89 3.9 79 3088 0.523 .383 24.6 8.8 31.7 15.3 5.1
Charles Barkley PHI 1987-88 3.8 80 3170 0.490 .372 24.6 8.5 34.3 14.4 3.8
John Stockton UTH 1987-88 1.0 82 2842 0.536 .410 24.3 9.7 20.3 4.0 19.1
David Robinson SAS 1990-91 5.0 82 3095 0.525 .374 24.1 8.5 32.6 16.5 3.2
Ben Wallace DET 2001-02 4.5 80 2921 0.537 .384 23.4 8.9 10.0 17.1 1.9
  • It is dominated by players from the 80s/early 90s
  • It lacks shooting guards. It's quite amazing how much better Michael Jordan was than the next-best shooting guard(s) of all time. Only 4 player seasons crack the top 10 shooting guard seasons (Clyde Drexler, Brent Barry, Michael "Sugar" Ray Richardson, and Rodney McCray. I'll go out on a limb and say that three of those won't go over well with the "YAY! POINTS!" crowd).
  • David Robinson was spectacularly good. History seems to have forgotten this. Sure, history acknowledges that he was great, but if you walked into a bar and said the Admiral was better than Wilt or Kareem, you'd be laughed out of the place, even though his career stats are nearly identical with Shaq's, except better defensively across the board. And if you said Shaq was better than Wilt or Kareem, lots of people would at least listen to your argument about how Shaq would stomp all over the skulls of those little people in Wilt's era.

Which leads me to my next point. I wondered about the dominance of the 80s, and asked some others, including Dave Berri, about it. One possibility is that those Dream Team members were just so damned good. There are other plausible explanations, though:

  • The underlying population base has expanded over time. More foreign players are in the league (and they are better than before). So today's players, like LeBron or Durant, face much stiffer competition. There is some evidence of this by just glancing at the numbers -- Rodman's rebounding doesn't happen today, shooting guards don't post Jordan's point totals. And the crazy high assists combined with super-efficient shooting of Magic and Stockton doesn't happen today either (of course, that fits the "they were just that damned good" theory as well).
  • Defense might also play a role.  In the past, teams did not have the defensive schemes we see today (the so-called Thibodeau Effect). That might also diminish the offensive numbers.
  • Pace of play has slowed down a lot. This would impact ADJP48. Perhaps that would also increase the spread between a great player and the average (hence increasing WP48). In general, a faster pace favors good players' WP48 scores (more opportunities per 48 minutes to grab rebounds and hit shots), and makes bad players look even worse (more opportunities to miss shots, foul, or turn the ball over).

A word of caution, though: it's easy to fall down the rabbit hole on all of this. If you really want to compare players in different eras, go right ahead. But this will always remind me of arguments like, "Would Han Solo or James Kirk win in a fist fight?"

Players in the 1980s only played against players in the 1980s. And players today only against players today. We suspect athletes have gotten better. But actually measuring this in a team sport...well, that is hard, thanks to interaction effects. I've never seen any attempt to do this that didn't leave me skeptical.

For now, enjoy browsing the dominance of Dennis Rodman, and the next time someone tells you that that first Bulls Threepeat team didn't have a dominant big man, slap them in the face with the awesome glory of Horace Grant.