Off the top of his head, Celtics president of basketball operations Danny Ainge guessed that maybe 20 players have scored 36 or more points in a game at least twice this season. He was close. There have been 18. One is Celtics forward Jeff Green, who accomplished the feat within a span of two weeks, scoring a season-high 39 points at Washington Jan. 22 and then scoring 36 against Philadelphia Wednesday night. Kevin Durant, Carmelo Anthony, Paul George, Kevin Love, and others of that ilk comprise the rest of the list, which is a who’s-who of the NBA’s most elite and consistent scorers. “I don’t see Jeff as one of those,” Ainge said Thursday. “I see him as a guy that is capable of scoring a lot of points on any one given night, but he needs help — like all players do — to be efficient and score.” As the Celtics prepare to face Sacramento Friday at TD Garden, Green is averaging a team-high 16.3 points this season, but he has had wild swings in production. For instance, two games after scoring 39 against the Wizards, he scored 8 in a loss. Even within games, he disappears for long stretches — even for a half. But then there are nights when Green’s talent, speed, size, skill, and athleticism are on full display and he scores so much so easily that fans wonder why he doesn’t play like that more often.