The need for speed and threes has left the NBA and its 2018 draft class in a peculiar position. Seven of the class of 2018’s top prospects are traditional back-to-the-basket power forwards and centers auditioning for a league that has mostly chosen not to cast that part in recent years. The Golden State Warriors’ “death lineup” places 6-foot-7 Draymond Green, a career 33-percent three-point shooter, at center. The Cleveland Cavaliers roll with 6-10 Kevin Love, 36 percent all-time from three-point range, in the middle. And with defenses happy to hack the likes of DeAndre Jordan and Andre Drummond — both traditional, on-the-block bigs — the nature of power forwards and centers is entirely different than even five years ago, when the plodding Roy Hibbert led the Indiana Pacers to a division crown, and Jordan helped the Los Angeles Clippers to one. Hibbert, an all-star as recently as 2014, is now out of the league. Now the changes in the key tasks of pure post-up players have come into focus the same year the coming draft class features a glut of those players.