As far as I can tell, Stephen Curry holds the rookie record with the most three's in a season with 166 in 09-10, beating Rudy Fernandez's record of 159 from 08-09. Lillard currently has 111 three's in 49 games which puts him on pace to hit 185 three's this season if he plays all 82 games.
That would be quite the accomplishment, I don't think Lillard's greatest attribute is his three point shooting but as a rookie he's really showing that he can shoot it. Even though Dame's percentage from the is 36% compared to 43.7% in Curry's rookie year, but I don't think it diminishes Lillard's accomplishment thus far. What do you guys think?