Laine now has 19 goals in 22 games, which puts him on pace for 71 this season.
Now, before anybody goes crazy, let me be clear that I'm not predicting that he'll actually score 71 goals, but simple arithmetic shows that he's on track for that many, as of right now.
To hit 50 this season, he'd have to score 31 goals in 60 remaining games, or .517 goals per game. Last season he scored 44 goals in 82 games, or .537 goals per game. In other words, from this point on, Laine can score at a lower rate than he scored last year, and still get 50 goals. If he spends the last 60 games this season scoring at the same rate he scored at last season, he finishes with 51 goals.
So, barring injury (the dark horse in all predictions), if you believe that Laine is a better player at age 20 than he was at age 19, it's pretty much a no-brainer that he scores 50 this season.