Thursday, May 21, 2015

NBA ICBM’s: From Temptation to Necessity?


MVP Steph Curry’s 286 successful field goals from behind the three-point arc, a new league standard, are more than all but five of the NBA’s then-22 teams attempted 36 seasons ago when this almost exclusively late-game “novelty” was implemented. More – six, including the champs – averaged fewer than two attempts per game. The Houston Rockets, currently squaring off with Curry’s crew for the Western Conference Championship, launched over four times as many treys as the most prolific mad bombers from that inaugural season, ironically (or maybe not?) the then-San Diego-based Clippers.

In the game of today, an open look from 24 feet is more valued than the same shot from a step or two closer. And given the way so many guys shoot free throws, maybe even twelve- or fifteen-footers have become similarly undesirable.

Under the helm of an analytics-driven GM and RedAuerbach-bred coach, the Rockets took 799 more three-pointers than did their opponents, far and away the season’s largest differential. (I’m not sure if this is the greatest gap ever. The only comparable output over the past four seasons was Orlando’s +593 in the 66-game slate of 2011-12, 9.0 compared to Houston’s 9.7 per game.)

The Warriors are none too bashful themselves, posting a +460 in three-point tries, good for No. 3 in the league. And the Eastern Conference Finalist from Ohio stands fourth (+405).

The opposite end of that spectrum has consistently included Washington (-504, No. 27) and Memphis (-643, No. 28), both successful playoff squads of late. Alas, over the last four seasons, only two teams sporting a negative in three-point attempts have advanced to Round 3, Memphis (-381, No.29) two seasons ago and the 2012 champion Heat (-288, No. 27).

Naturally, it’s important to, ya know, make your share of these shots, even moreso to keep the other guys from doing so.

As improbable as this may seem, there were seven teams who earned a Top Ten rank this season in both shooting and defending three-point shots. (Even more improbable might be that none of those teams is named the San Antonio Spurs, whose No. 27 position on the defensive side of things did not bode well come playoff time.) Two of them, Golden State and the up-and-coming New Orleans Pelicans, reside in both Top Fives. Three of them – the Warriors, Hawks and Jason Kidd’s surprising Milwaukee Bucks – hold similarly elite standing, both offensively and defensively, in overall field goal shooting.  (The 67-win Warriors stand Top Five in this regard as well – not to mention in both offensive and defensive rates of conversion.) The other Masters of the Arc are the Blazers, Bulls and LeBrons.

In Tuesday’s series-opening loss in Oakland, Houston took only 22 treys – second fewest in their 13 playoff tilts so far; 11 off their season average; a mere 26 percent of their shots from the field (compared to a whopping 39 percent on the season).

Golden State utilizes the arc on 31 percent of its shots, seventh most during the regular season. The Eastern Finalist Cavaliers (33 percent, No. 2) and Hawks (32 percent, No. 4) rank highly on the usage chart as well.



Let’s take another quick look at the numbers from that Warrior-Rocket opener. Each team wound up with exactly 100 possessions. Each team suffered 47 empty possessions (TO’s + missed FG’s – OR’s). Each team, consequently, posted a conversion rate of .530.

Golden State made two more three-pointers and missed two fewer foul shots in their four-point victory. Hmm!

Essentially, two missed free throws squander one instance of successful offensive execution. By the same logic, two treys provide a bonus conversion. Houston’s 10 foul-line misfires cost five conversions and their eight threes compensate for only four. Their adjusted rate of conversion dips to .520, while the Warriors’ improves to .540 when so altered. 

[This adjusted rate of conversion matches up rather well with the points-per-possession stat. Here’s a more detailed look at one team’s “conversion.” ]

Maybe the real measure of the value of the Arc is the adjustment it imposes upon a team’s rate of converting their possessions – and, of course, its impact on the scoreboard.

Five teams padded their conversion total by an average of two or more per game …

… among them, all four conference finalists.