Jayson Tatum is ahead of schedule. Young players usually struggle in their first year, but Tatum has fit seamlessly onto the team with the best record in the NBA. He is averaging 13.7 points, 5.4 rebounds, and 1.5 assists a game, and he’s shooting higher percentages from the field (49 percent) and the 3-point line (47.8 percent) than he did in college. The no. 3 overall pick hasn’t had to deal with too steep of a learning curve. Tatum is in a great situation in Boston, but none of the other lottery picks in this year’s draft would have done more with the opportunity, and few would have come close.

The most important thing Tatum does on offense is stay out of the way. He is a spot-up threat off the pick-and-roll between Kyrie Irving and Al Horford, the foundation of the Boston attack. The defense is often rotating when he gets the ball, and he either has an open look or the chance to attack a defender who is closing out on him. It’s a much different role than he had at Duke, where he was the focal point of the game plan. The Celtics do a good job of getting him the ball on the move, running him off screens and dribble handoffs rather than letting him dribble the ball into the ground like he did in college. According to the tracking numbers at Synergy Sports, Tatum went from getting 22.8 percent of his offense from isolations last season to only 8.9 percent this season.

Tatum gives Boston lineup flexibility on defense. At 6-foot-8 and 205 pounds with a 6-foot-11 wingspan, he has the size and speed to switch screens and defend multiple positions. He was primarily a small-ball 4 at Duke, but he could be playing at the 2, 3, or 4 in Boston, depending on the lineup and the matchup on a given night. While he doesn’t have elite physical tools, he’s a smart player with quick hands, and the Celtics put him in good situations to succeed. Jaylen Brown and Marcus Smart, two of the best perimeter defenders in the NBA, typically get the tougher assignments, and Tatum has the versatility to handle whoever is left. He is in the 60th percentile of players leaguewide when defending the ball handler, and in the 88th percentile against the roll man.

Celtics coach Brad Stevens doesn’t believe in traditional positions. He classifies players in three groups: point guards, wings, and big men. Stevens has cycled through several starting lineups following Gordon Hayward’s injury, but he typically closes games with one point guard, three wings, and one big. He prefers those lineups because he wants as much shooting, playmaking, and defensive versatility on the floor as possible. Putting three shooters around the pick-and-roll forces defenders to cover more ground to send help, and it’s harder to move the ball against lineups with three wings who can switch screens and cover ground on the perimeter. The philosophical clash between small ball and big ball is over. Medium ball has won the day.

Boston’s minutes distribution this season is fascinating. Stevens has gone deep into his bench without Hayward, with 11 players getting regular playing time. There are three big men (Horford, Aron Baynes, and Daniel Theis) who average a total of 63.1 minutes, five wings (Tatum, Brown, Marcus Morris, Smart, and Semi Ojeleye) who average 130.9 minutes, and three point guards (Irving, Terry Rozier, and Shane Larkin) who average 64.7 minutes. The wings in Boston are playing more than the big men and point guards combined. If Hayward were healthy, the disparity would be even more pronounced.

With so many minutes available on the wing, it was easy for Stevens to find a role for Tatum as a rookie. He has even found immediate playing time for Ojeleye, a 6-foot-7 wing from SMU whom they drafted with the no. 37 overall pick. The situation would have been different if the Celtics had taken a big man or a point guard instead. There would be no place for them in the rotation. Boston has veterans at the 1 and 5 and spends most of the game in three-wing lineups.

With three-wing lineups becoming increasingly popular, the way NBA teams look at the draft needs to change. Under more traditional models of team building, NBA teams needed three point guards, five wings, and five big men on their roster. Big men played at the 4 and 5, wings played at the 2 and 3, and point guards played all of the minutes at the 1. In today’s more fluid era, wings get most of the playing time at the 2, 3, and 4 positions, and there are even situations when they play at the 1 and 5. Logjams at the wing position don’t exist anymore; there will always be a place for them to go. Conversely, unless a point guard or a big man is special, they will spend most of their time on the floor at the 1 or the 5, respectively, which means the competition at those positions will only get more intense.

Rookie point guards need the ball in their hands. A lifetime of dominating the ball at the lower levels meant they never learned to play without it. Most struggle with their outside shots early in their careers, since it was so easy for them to use their size and athleticism to get to the rim in high school and college. They don’t offer much value if they are playing off the ball. None of the five point guards taken in the top 10 this year have been consistent shooters as rookies. If they had been drafted by Boston, they would have needed to space the floor for Kyrie, and their inability to stretch the floor in that role would suffocate the offense:

Rookie Point Guards Struggling From 3 Top-10 Rookie PGs 3PA/G 3P% Top-10 Rookie PGs 3PA/G 3P% Markelle Fultz (no. 1) 0 0 Lonzo Ball (no. 2) 5 25.7 De'Aaron Fox (no. 5) 1.4 27.6 Frank Ntilikina (no. 8) 1.8 25 Dennis Smith Jr. (no. 9) 5.3 29.7

Teams that draft point guards have to choose between two difficult paths. They can either deal with the growing pains that come with learning the position (and lose a lot of games in the process), or they can try to move them off the ball, changing their game and what made them special in the first place. The worst-case scenario is what happened to Orlando with Elfrid Payton. The Magic made Payton the starter from day one and would suffer with a bottom-10 offense in each of his first three seasons while they waited for him to figure out the position. And despite all the time they invested in Payton, he may turn out to be nothing more than an average NBA point guard.

The transition to the NBA is just as hard for big men. With so many teams playing wings at the 4, there are fewer minutes available for bigs than ever before. Traditional power forwards now have to play as small-ball 5s, and most teams have more centers than they can use. The center is the only big man on the floor for most of the game, which increases their defensive responsibilities. They are the quarterback of the defense. They have to protect the rim, recognize what the offense is doing, and coordinate the movements of their teammates. It can take years to grasp all the mental nuances necessary to play the position, and all that development can be wasted if a team gets another center. Logjams up front form quickly, and big men who can’t get playing time have no trade value.

The Sixers found that out the hard way when they took Nerlens Noel, Joel Embiid, and Jahlil Okafor in consecutive drafts. Embiid is a transcendent talent, and as soon as he showed he could stay healthy for any length of time, he made their other big men redundant. Philadelphia didn’t get much for Noel, and it can’t even get a second-round pick for Okafor. Teams that spent lottery picks on big men in recent years could have a similar dilemma in 2018. What do the Kings do with Willie Cauley-Stein and Georgios Papagiannis if they draft DeAndre Ayton?

It’s very early in the process, but the 2018 draft is projected to be loaded with big men at the top. There are three in the top five of ESPN’s current rankings (Ayton, Marvin Bagley III, and Mohamed Bamba), and two more (Jaren Jackson Jr. and Robert Williams) in the top 10. Only four wings (Luka Doncic, Michael Porter Jr., Miles Bridges, and Kevin Knox) cracked the top 10. Regardless of whether those wings are better players in a vacuum than their peers, their value is going to rise on draft night because it will be easier for teams to fit them into their system. That goes double for guys projected to go later in the first round, since teams won’t reshuffle their rotations to get them playing time.

Of course, there are no sure things in the draft at any position. Orlando took Mario Hezonja with the no. 5 pick in 2015, and he has never been able to crack its rotation. One shouldn’t generalize too broadly based on what happened to the Celtics with Tatum. Most lottery teams don’t have All-Stars at point guard and center, and he has benefited immensely from playing with Kyrie and Horford. Few rookies will ever be as productive on a winning team as Tatum. For rebuilding teams, the more pressing concern is finding players who can fit together. Building a team through the draft is all about putting together pieces to a puzzle, and wings are much easier to build around than point guards and big men.