Mendoza line

I would say that there was a significant turning point during the 2015/2016 NBA season, the Warriors, on their way to 73 wins (but no championship) had an offensive rating of 114.5 for the season, 8.1 pp100 higher than the league average and 15.7 higher than the bottom of the league 76ers.  That world is largely gone, a 114.5 rating would have been 4th in the league last year and it would be 4.1 pp100 better than the league average, and 10 points above the bottom.  GSW still had the top offense at 115.9, but the median caught up by 2.7 pp100, and was up about 5% over the 15/16 season.  There has also been a small decline in oreb% over that span, which is part of a longer and deeper decline. 

This shift has significantly decreased the value of a specific type of player, ironically one that those same Warriors just handed a max contract to.  The math here is fairly simple, an average ortg of 105 is equivalent to a TS mark of 52.5% if we assume that turnovers and offensive rebounds basically cancel each other out in terms of total possessions, the decline in oreb% has actually made this not true anymore, with the average team grabbing 10.3 orebs a game to 14.1 TOs a game last season, so a 54.6% TS rate is needed to bridge that gap at a 105 ortg.  At a 110 ortg the average TS mark needed is 57.2%.

So lets talk about a few players, D'Angelo Russell first.  His best season to date had him with at 53.3% TS mark and a 31.9% USG with a fairly average TO rate.  5 years ago his teammates would have needed to average a 55.5% TS mark on the court next to him to pull the team's ortg up to average, last season it would have to have been 59%.  This is a large jump and a major reason why Brooklyn's ortg with Russell on the floor was almost 2 points below the league average, despite him playing over 60% of his mins with Joe Harris and his 65% TS mark.

The numbers are similar for Russell Westbrook's (what is it with Russells?) career averages, and much worse on his last season numbers.  But even worse is that these two players are joining the top two offenses in the league, even with lower usage rates than in previous years their negative impacts will be hard to cover over.  Assuming a 25% usage rate the rest of the Warriors would need a TS mark of almost 70% to keep their offense at the same level, and to put that in perspective the average Steph Curry 3 has a TS rate of 65% so even an offense that was 25% D'Angelo and 75% Curry 3pters (with average rebound and TO rates) would be notably worse than last year's Warriors offense.  Their offense is going to look especially anemic when Curry sits while Klay recovers from his ACL tear. 

Westbrook is harder to guess at, he has had large swings in his efficiency over the past few years, but at 31 he is unlikely to have a career best season in TS, and his career best of 55.4% isn't exactly great.  He also hasn't accepted a role with sub 30.9% TS in the last 9 seasons despite playing most of that time with either Durant or Paul George, so I expect high usage/low efficiency for him as he runs himself into decline. 

We can apply this to other players in the league, Andrew Wiggins looks like a terrible bet to be a valuable contributor with one caveat.  His low, low TO rate which gives a glimmer of hope, as Minnesota managed the #4 offense in the league two seasons ago thanks to the #1 TO rate and the #4 oreb rate, as well as the #3 FTr.  Of course that was with Towns and his high efficiency scoring.  Mitchell in Utah is another candidate for dumping while he is at peak value, because if he is still scoring at this level when the league catches up to these shifts he will be untradeable on what is likely to be a max contract in 2 years time.  Dennis Smith Jr is another who should be jettisoned ASAP, and Denver needs to do some serious thinking about Murray.