NBA Analytics Reveal Coaching Negligence

Hi everyone, I know there are some threads this season already about how terrible Keith Smart is as a coach. Being a fan of sports analytics, I wanted to present a factual and quantitative basis for some more solid grounding behind the Fire Keith Smart movement.  I'll start by quoting a recent ESPN article by Ethan Strauss where he is critical of Smart:

A few times this season, Smart cited “the tape,” as though obscure snippets of Warriors footage contained what I lacked in maturity and common sense.  “See you look at the stats...I watch the tape.” 

I think this epitomizes what is wrong with Smart.  The NBA is moving towards all sorts of advanced stats that can quantify exactly how good each player is, down to how effective they are at exact distances from different parts of the floor, or which combinations of players play the best together as a unit and at what times.  The Warriors (or at least their coach) seem a bit behind on the curve on this, relying on the "old school" method of judging based on imperfect eyes, memory, and human biases to inform decisions.  It's not that watching tape is necessarily bad (though it could be, under non-expert or subjective eyes).  Smart seems to rely on his 'favorite guys', players he (improperly) trusts for whatever reason, over what is in the best interests of the team as born out by quantitative analysis.

Consider the following: Both win-shares and PER show that Stephen Curry, not Monta Ellis, is the Warrior's best player.  Adjusted per-48 minute or per-36 minute stats show that Stephen Curry and Reggie Williams are some of the team's best players who are being under-utilized.  Check this out.  Another stat called adjusted plus/minus (developed by a MIT and Stanford Ph.D grad) shows that Biedrins and Ellis are the two most harmful players on the team.  In the prior link this metric is described as, "... an advanced statistical approach to estimating a player’s effect on the game while controlling for the performance of his teammates and opponents." Ellis, even adjusting on a per-minute basis so he isn't punished for playing so many minutes on a losing team, puts the team in a huge hole simply by being on the floor.  Based on adjusted defense figures, it should be noted that Curry is poor defensively as well, however is defensively better than Curry or Lee, and is so much more efficient offensively than Ellis that he is significantly more valuable as the team's best player across multiple measures.  Of course, not all stats are representative of the truth, so let's look at some others.

These floor time stats, adjusted per-48mins, are also critical of Ellis (see 'on/off net'), however still show that Curry, Williams, Udoh, and Lin are severely under-utilized even when accounting for the competition they face when they actually play. In fact, over the entire season, on a per-minute basis the team ends up increasing leads or closing the gap the most (adjusted plus/minus) when Udoh or Lin are on the floor.  I was a bit skeptical of this, especially for Jeremy Lin, however this is what I found when looking at Lin's last 4 games:

April2-Mavericks.  Ellis +2 in 44mins, Lin +6 in 6.5 mins.
March30-Grizzlies. Team lost by 19. Ellis -19, Lin +2 in 15 mins, the only positive plus/minus on the team and went 4/5 from the field.
March1-Pacers. Team lost by 9. Ellis -14. Lin +10 in 6 minutes.
Feb25-Hawks. Team lost by 16. Ellis -25. Lin +10 in 10 mins.

The NY Times covered the validity of adjusted plus/minus before even for players with limited playing time, and noted how reliable the stat has been over the past few years in helping clever teams identify under-utilized players languishing on other teams.  On a side note, Acie Law has one of the worst adjusted per-minute or per-48 plus/minuses on the entire team - the reason for this is while he is average offensively, he is one of the absolute worst in the league in defense, where his net effect as a player is as one of the most harmful players for winning for his team when he is on the floor.  It appears from this article that Law, a journeyman with 5 teams in 4 seasons already, is benefiting from blind, biased trust from his coach (which also explains why Ellis plays so many minutes): "I'm forever indebted to Coach," Law said. "I text him all the time and tell him, 'Thank you.' He trusts me. He's giving me a great opportunity. It feels great to finally be playing at this point in my career."

So what does this all mean?  Stephen Curry is the team's best player, but only plays 33 minutes a game and sits during many key periods of games. Reggie Williams, by the metrics, should be a starter (or at least play starter minutes), but he rides the bench.  Udoh and Lin are young players but lead the entire team in adjusted plus/minus, yet don't play much.  This coaching negligence is even more problematic given that the team is mathematically out of the playoff race, and the Warriors could benefit from a better lottery pick plus more experience for younger players, but Smart keeps playing  veterans insane minutes in a desperate attempt to win and keep his job.  At this point in the season it's completely irresponsible and against the interests of the team to keep playing starters 42+ minutes. On a side note, Lin doesn't appear on the league's per-minute leaders because he doesn't qualify for the minimum 500-minute cutoffs, but if my math is correct he currently leads all NBA guards in per-minute and per-48 minute steals and blocks.  I acknowledge I've put a bit more emphasis in this post on Jeremy Lin, and it's because I have watched him extensively in the Boston area while he was a star at Harvard.

Keith Smart often rebukes media or others who question him from the perspective that he simply knows more.  Some good coaches rely on their own extensive NBA playing experience to succeed, while other good coaches have proven success from learning as assistant coaches in winning organizations.  Keith Smart has neither - he has not been associated with success in any coaching capacity, and while he likes to reference his NBA career, this is a man who played 2 games and a total of 12 minutes professionally.

If Lacob is serious about rebuilding the Warriors, he must replace Keith Smart (and Riley for that matter, but this deserves its own post).  Lacob likes to reference being associated with the Celtics rebuilding process.  As someone who watched dozens of near-court-side games every season during Boston's pre-Big3 era, I can say that the Celtics rebuilt a team with little talent and a horrible cap situation by doing the following:
-> getting rid of long, overpaid contracts, even if it meant giving up player assets or draft picks
-> drafting well, and giving the young players large amounts of playing time - even if it meant losing a few more games both to improve these players as well as to improve lottery picks
-> accumulating large 1 or 2-year expiring contracts (even giving up players or picks to get them), and leveraging these contracts in later trades
-> even for draft picks who didn't pan out, continue to develop them as attractive trade bait, and develop enough assets (with enough game minutes to put up some stats) to package them together for elite players.
-> not re-signing players to long, large contracts unless they are elite, and not overpaying even if the team is lousy.
-> over time, making most of the roster with movable short term contracts.

Over a period of several years, the Celtics got out from Vin Baker's alcoholism and mammoth contract, while acquiring, drafting/developing, and then trading Ricky Davis, Marcus Banks, Al Jefferson, Raef LaFrentz, Jiri Welsch, Delonte West, Wally Szczerbiak, Ryan Gomes, Theo Ratliff, Tom Gugliotta, plus draft picks, in order to end up with a core of the Big3 plus a young Rajon Rondo and a young Kendrick Perkins.  Rondo, Perkins, Jefferson, West, Banks, and Gomes by the way, all struggled during their first year or two, however the organization continued to develop them with significant playing time either to make them a trade-able asset or for their own future with the club.

One of the first moves the organization did as well, probably most importantly, was fire and replace the head coach.

This FanPost is a submission from a member of the mighty Golden State of Mind community. While we're all here to throw up that W, these words do not necessarily reflect the views of the GSoM Crew. Still, chances are the preceding post is Unstoppable Baby!

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