Joe Harris, fresh from the D-League, couldn't believe what Brooklyn's new coaching staff was telling him in training camp.

"We pushed him to be our Kyle Korver," Kenny Atkinson, Brooklyn's head coach, told ESPN.com. "And he was kinda like that battered little doe you find in the forest. He had no confidence."

But the Nets knew Harris could shoot 3s, and they would figure out the rest later. Ditto with Justin Hamilton, a journeyman center the NBA discarded for Europe because teams didn't think he could do anything but maybe kinda shoot 3s.

Small decisions like these across the league are driving the unprecedented boom in 3-point shooting. If you can make shots that count for an extra point, the NBA will find a place for you. Just survive on defense, and you might steal minutes from a shakier shooter who outdoes you in every other facet of the game. The NBA, in doling out roster spots and playing time, is erring on the side of shooting more than ever before.

The 3-point explosion is not new, though it is accelerating. The NBA smashes the all-time record for 3-point attempts every season. A full 31 percent of shots have come from deep this season, up from 28.5 percent last season and a positively charming 24 percent in 2012-13. It is not stopping anytime soon.

Critics have been protesting for years. They mostly worried about style: Do we really want to watch teams chuck 80 combined 3s in a fast-paced pickup game? What would happen to the midrange game and post-ups? Even league officials fretted. David Stern, the former commissioner, joked in 2013 that, "When our teams are hot, it's a thing of beauty. And when they're not, they can go 3-for-41." Editor's Picks Zach Lowe Q&A: Nikola Jokic on Denver, Serbia and his evolving game

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This season may mark the point at which stylistic objections merge with substantive ones. The league is on pace to break the all-time record in points per possession, due almost entirely to the 3-point bonanza and its ripple effects. The league overall is pouring in about 105.5 points per 100 possessions, already way over last season's final average, and dead even with the three or four most prolific scoring seasons in history, according to data provided by NBA.com.

Offense tends to surge as the season goes on. The past month was one of the most bountiful scoring feasts ever. If that keeps up, the NBA will reach unprecedented efficiency territory. Coaches don't worry so much anymore about how the triple-heavy game looks. They worry about whether ultra-modern lineups, with five 3-point shooters, will stretch defenses beyond the breaking point.

"The floor is just so spread out," Brad Stevens, Boston's coach, told ESPN.com. "You have to scramble against guys 24 and 25 feet from the rim, and that just opens up every driving lane."

"What can we even do to minimize the 3-point shot?" Toronto coach Dwane Casey asked. "Do you just stop protecting the paint? Do you really want to just say, 'Go ahead and make layups?'"

Casey, by the way, is an active participant in a revolution that once troubled him. He started Patrick Patterson, his backup stretch power forward, in six consecutive second halves over Pascal Siakam -- an energetic rookie serving mostly as a token starter. It's hard to imagine the Casey of even two or three years ago pulling that in the regular season. "We're doing it too," he said. "You almost have to go smaller right away, or get more shooting out there, just to compete."

League officials track the numbers, and they know coaches wonder when good team defense as we have traditionally measured it might become impossible. Does the NBA want the equivalent of a 53-47 National Football League game? "It's an interesting question," said Kiki Vandeweghe, the NBA's executive vice president of basketball operations. "And it's a good problem to have."

For now, everyone is waiting to see what happens over the last 40-plus games -- and if the scoring explosion is real.

Maybe it's all just an illusion. We see fast breaks and 3-point barrages, and assume something new is happening. Maybe pace is tricking us. The league has seen per-possession scoring at this level before, including in the three seasons leading to the 2011 lockout -- not that long ago! The 3-boom was in its relative infancy then, and offenses were still killing it.

The Steve Nash-Mike D'Antoni spread pick-and-roll had, well, spread across the league, and referees permitted zero handchecking. The drive-and-kick attack flourished. Nobody wept for helpless defenses then. Tom Thibodeau was in his lair in Boston, crafting a solution that would reverse the trend after the lockout -- and nudge offenses toward more trickery and complexity. Defensive masterminds are tinkering with new counter-revolutions.

Teams in the D-League that have experimented with extreme triple-happy offenses haven't produced points per possession numbers any better than the best teams pump out now. Maybe there is a ceiling on scoring regardless of what types of shots you take.

Elite teams are also disproportionately skewing this season's overall average. Can that last? Golden State and Toronto are threatening the all-time team scoring efficiency record. Houston is nipping at their heels. Cleveland looms, playing all-shooting lineups more in crunch time -- even if it means going without Tristan Thompson, their anchor on defense.

The first three are outscoring the 2008-09 Suns, the best offensive team that season, when the league's overall average surged to 105.4 points per 100 possessions -- tied for the highest mark ever excluding one season (1994-95) in which the league moved the 3-point line in. (How quaint does that seem, by the way?)

The league is top heavy, even by its standards. A few teams hoard an unusual number of top-20 players. The crazy cap spike allowed the 73-win Warriors to sign Kevin freaking Durant with cap space.

When we plot team-by-team scoring numbers on the chart below, the gap between this season's line and those of last season and 2008-09 is fattest at the top. In other words, the very best offensive teams are driving a large part of the improvement:

Mapping points per possession from the NBA's best offense (No. 1) to worst (No. 30). Neil Jamieson

Once cheapo contracts linked to the old cap regime cycle out, there should be some talent dispersal that weakens the behemoths behind the scoring boom. Think about the most intriguing Paul Millsap trade destination: Toronto. Are the Raptors really going to pay Millsap, Kyle Lowry, and DeMar DeRozan $100 million combined every season once Lowry and Millsap sign their new deals? If they are, some other good players are leaving Canada.

Those Raptors have enjoyed pristine roster continuity even while the cap spike sent players flying around the league. It takes time to develop chemistry. A very good team that already has it can prey on weaklings integrating a bunch of new guys learning a new defensive scheme.

We've also hit a rare point at which no one is tanking. Add a few self-saboteurs to the mix, and the league's overall scoring average might drop toward normalcy. (That is uncertain, since the other teams might puff up their own scoring numbers by blowing away the tank brigade.)

In other words: There are reasons to believe the jump in scoring is a random, self-correcting blip.

But almost everyone scored like bananas over the past month, and it is starting to look like something might be happening. The Rockets represent the most spectacular case. They are taking a crap-ton of 3s -- a record number -- and their success on offense suggests the NBA hasn't yet wrung all it can from tweaking shot selection.

Teams have jacked up their 3-point attempts without sacrificing shot quality. They can go even further. Catch-and-shoot triples -- the juiciest ones -- account for about 73 percent of total 3s, just as they did last season. About 41 percent of all 3s have been "wide open," per SportVU data, a slight uptick over last season's share.

More players are comfortable letting fly from well beyond the arc, and some proficiency in off-the-dribble 3s -- once a heretical shot for the Eric Snow and Professor Andre Miller, Ph.D., types -- is part of the starting point guard job description now. Those trends aren't reversing themselves.

"I don't think we're at or near the point where 3s will top out," Vandeweghe said. Team officials and analytics gurus agree almost universally.

The jump in three-shot fouls -- i.e., shooting fouls on attempted 3s -- has outpaced the rise in overall attempts, per ESPN Stats & Information. Turnovers are down, perhaps in part because teams are taking more 3s early in the shot clock, according to NBA.com shot-tracking data. At the same time, steals -- live-ball turnovers that lead to layups and dunks -- have held steady.

Offensive rebounding and free throws have stabilized after years of consistent decline. Maybe there is a floor for those "other" paths toward points, even as teams launch more and more 3s.

Team officials privately worry how deadly offenses could become if the league returns to the zero-tolerance policy on handchecking that helped boost pre-lockout scoring numbers. It's hard to prove, but most coaches and front-office executives agree defenses get away with a little more bump-and-grind than in the mid-2000s -- when the NBA was obsessed with creating a more viewer-friendly game. The league has heard the concerns, and is monitoring the handcheck stuff. "That area is tough -- the freedom of movement, especially away from the ball," Vandeweghe said. "It's tough for referees to watch everything. But I think we've found a good balance."

(As an aside, Vandeweghe confirmed the controversial last-two-minute reports aren't going anywhere. In fact, he said the NBA would "probably" start releasing full game reports at some point.)

Coaches deploying more shooters over defensive specialists could be creating some powerful snowball effects. Fewer defense-first guys being on the floor means scoring is easier for everyone. When scoring is easy, teams might become complacent on defense, figuring they can just get it back on the other end. Fast breaking at every opportunity takes a physical toll; players have to sneak in rest, and they might exhale when the other team has the ball.

Coaches are perfectionists. They want to field lineups that can play airtight defense. But the math is so stark, they feel almost compelled to stock the floor with shooting at the expense of size, rebounding and defense.

The braver they've gotten with all shooting, all the time, the more they've realized the tradeoffs appear to work in their favor. Three is so much more than two, and the threat of a 3-pointer makes the best 2s easier to find; the league is on pace for its highest 2-point shooting percentage ever, according to research from pocket square king Kevin Pelton.

"We've already reached the point where we are willing to give up some 2s, even near the basket, to prevent corner 3s," Gordon Hayward told ESPN.com. He ain't lying.

Smaller shooting-heavy lineups compensate for size deficits by switching across several positions on defense. Switching used to make most coaches queasy. They felt vulnerable on the boards, and the sight of a large person posting up their point guard sickened them.

Those mismatches hurt now and then. Against some opponents, they hurt a lot. But as teams get better at switching, gang rebounding, and preventing entry passes to post-up brutes, the math nudges back their way. Switch with 10 or 12 left on the shot clock, and the opposing offense has precious little time to exploit any mismatch down low.

Post-up bigs who can't shoot 3s or defend smaller players -- Greg Monroe, Jahlil Okafor, Al Jefferson, Enes Kanter, Nikola Vucevic -- have already been relegated to bench roles. The nostalgic worry Houston-style offenses might play them out of the league entirely.

"If your big guys don't dominate, you have to go small," Casey said. "I tell Jonas [Valanciunas]: 'Oh, you want to play more? Then dominate. I don't want to see fadeaways over 6-8 guys. Get to the rim. Get every offensive rebound. If not, you're coming out.'"

Extinction seems farfetched, and the new big-man archetype is even more exciting to watch. We're already seeing it with Joel Embiid, Anthony Davis, Kristaps Porzingis, Karl-Anthony Towns, and Myles Turner -- the big man who can do literally everything. We love Embiid pump-and-driving from deep for the same reason we love big men in the silly Taco Bell Sprite Kia Poulan Weedeater Skills Challenge at the All-Star Game: It's just cool.

Some low-post mastodons have already evolved to meet the moment. Brook Lopez and Marc Gasol tried 97 triples between them over 16 combined seasons before this one. They've fired almost 300 so far, and we're barely into the New Year. DeMarcus Cousins was a year ahead of them.

They've each hit with a surprising accuracy; opposing defenses haven't adjusted their pick-and-roll coverages to account for this new development:

"Teams still don't believe it," Atkinson said of Lopez draining 3s. "They just leave him open."

That will change. Teams are already starting to switch more against those guys, or at least recover to them faster. Bigs will have to learn to attack that gambit by rumbling into the post, working off the bounce, and whipping smart passes -- by toggling between lots of styles.

The league is betting that sort of versatility proves more entertaining than even a polished, repetitive post-up game or some Shaq-style brutality. They're probably right. (They are also pining for a new Shaq-ish player to bring some diversity. "If there's another Shaq," Vandeweghe said, "you can bet that team will post up a lot.")

Switching will become an even more sought-after skill as the cleanest way to snuff the drive-and-kick attack. Coaches say they will spend more time coaching that, and teaching proper defensive positioning -- stances, footwork -- so that guys of all sizes are better at keeping opponents out of the paint. "That technique on the ball is going to be so much more important than ever," Thibodeau said. "You have to contain dribble penetration."

Casey said he might devote more time to a zone defense in future seasons. A few team officials even proposed scrapping the defensive three seconds rule so that plodding rim protectors could stay on the floor.

If scoring becomes too easy, the NBA could always soften handcheck enforcement or give defenders the benefit of the doubt when airborne shooters leap into them.

We're not there yet -- or even close. The league should set the record for scoring efficiency -- but only by something like one or two points per 100 possessions. That's meaningful, but not worth a red-alert examination of the game. Offense may vault even higher as more teams exchange midrange 2s for 3-pointers.

There is a hard ceiling somewhere, and probably not too far from where the league is now. The game will still slow down in the playoffs, when teams have more time to scout. "Give a team seven games," Thibodeau said, "and they can really lock into you."

Most fans understand that a team can play hard, tough defense and still give up 120 points. They enjoy the fireworks. If fans eventually revolt at teams taking 40 or 50 3s per game, the NBA will have to make some stylistic adjustments. But it's unclear how much that sort of 3-point volume can really warp the underlying substance -- the per-possession numbers -- of the game.

"We love great competition," Thibodeau said. "I don't care if the score is in the 120s or the 90s. Great competition is great competition."