Tomase: Your periodic reminder that Jayson Tatum could make monstrous leap in Year 2

Jayson Tatum dunks on LeBron James
Photo credit David Butler II/USA Today Sports

It was the signature play of Jayson Tatum's rookie season, and had the Celtics reached the NBA Finals, it might've been the NBA play of the year.

Trailing by four points with 6:45 remaining in Game 7 of the Eastern Conference Finals, Tatum curled off an Al Horford screen to collect a Marcus Smart feed beyond the 3-point line before splitting three listless Cavaliers defenders with a pair of giant strides into the lane. The lone defender rotating to meet Tatum at the basket was one of the 20-year-old's childhood idols, but LeBron James arrived a half step late and a soaring Tatum had already committed to playing the part of the jackhammer.

The savage dunk he detonated on James energized the Garden crowd almost as much as Tatum thrusting his chest into the superstar in a youthfully rash display of exuberance. One possession later, Tatum drilled the 3-pointer that gave the Celtics their final lead of the season.

Unfortunately, he only took one shot the rest of the game, allowing James to dominate crunch time and secure an eighth straight trip to the Finals. The two then shared a lengthy embrace that symbolized the inevitability of the NBA's next generation.

The dunk showed us how good Tatum already is. But the postgame confab with the King pointed to something greater -- what he might eventually be.

As the Celtics gear up for training camp late next month in advance of their October opener, it's worth considering what kind of leap Tatum will make in year two.

The history of teenagers who debut like Tatum did -- averaging nearly 14 points a game while shooting over 43 percent from 3-point territory -- suggest that he hasn't even scratched the surface of his ability. His improvements over the next three seasons could end up being not so much incremental as exponential.

 Kobe Bryant debuted at 18, was an All-Star at 19, and became a 28-point per game scorer by 22. Kevin Durant debuted at 19, averaged 25 points a night at 20, and led the league in scoring for the first of three straight seasons at 21. Carmelo Anthony set a record for teenaged scoring average (21.0) as a 19-year-old and began posting 25 a night for a good at age 21.

Those are Tatum's comps because he looks like a future superstar. But the improvements second-tier All-Stars make over their first three seasons can be just as impressive. Paul George saw his point, rebound, and assist averages jump by 50 percent or more from his rookie year (7.8-3.7-1.1) to his third season (17.4-7.6-4.1). The same goes for James Harden, whose scoring averages in OKC rose from 9.9 to 12.2 to 16.8. On a smaller level, consider the leap teammate Jaylen Brown made from a reserve role as a rookie to a starter and star in the playoffs. What if Tatum similarly improves?

Tatum will not need to score like any of the above All-Stars because the Celtics boast a loaded roster and it's not necessarily in his nature to demand the ball, anyway. Bryant was a gunner from the womb, and he found his shot even on a title-contending Lakers team dominated by Shaquille O'Neal. Tatum seems more naturally inclined to score in the flow of the offense, which is how the Celtics can occasionally go long stretches without forcing him the ball; in the decisive moments of Game 7, for instance, C's not named Tatum went 1-for-10 from the field while Cleveland pulled away. It was an inexcusable lapse, because by that point, Tatum was already the team's best player.

So how might he improve upon his rookie performance? He arrived in the NBA sneaky strong, which allowed him to hold his own against power forwards when the Celtics went small. He's wiry but broad, with excellent instincts and long arms that make him a surprisingly effective shot blocker and ball hawk. There's no reason to think he won't become even more stout in this area as he adds muscle.

And extra strength will come in handy on the offensive end, too, because Tatum struggled to maintain ball control on drives to the basket. In the second half, especially, he routinely lost the handle on the way up while trying to score at the rim. Part of countering that is possessing the strength to withstand swiping defenders, and part of it may have been mental, too. In any event, he can become an even better finisher.

He should grow more efficient in that area by becoming more decisive. Tatum's effective field goal percentage on catch-and-shoots was nearly 70 percent. He shot over 50 percent when taking one or two dribbles. Anything more than that -- and to be fair, he often over-dribbled in isolation to beat the shot clock -- and his shooting numbers dipped into the 40s. He's explosive enough to catch and shoot or make a move before the defense can set.

Watching Tatum average 18.5 points a game in the playoffs clued us in to the player he could become on a nightly basis. He can already score at every level, justifying all of those post-draft Paul Pierce comparisons, and not even the Celtics could've seen that coming. Tatum makes pull-ups and fadeaways from intermediate distances, he possesses 3-point range at any point on the arc, he can post up or step back, and his long arms and even longer strides make him a threat to burst to the rim almost at will.

The best player in the world learned that lesson the hard way in May. There's no doubt more where that came from. The only question giddy Celtics fans must ask themselves is how much more and how soon will we find out?