Aids the eye in seeing patterns in the presence of overplotting. geom_smooth() and stat_smooth() are effectively aliases: they both use the same arguments. Use stat_smooth() if you want to display the results with a non-standard geom. geom_smooth( mapping = NULL, data = NULL, stat = "smooth", position = "identity", ..., method = NULL, formula = NULL, se = TRUE, na.rm = FALSE, orientation = NA, sho