Knots number issue

According to Wikipedia and other sources number of knots is:
knots = number_control_points + curve_degree +1

Then why does this happen?

import rhinoscriptsyntax as rs

control_points = rs.CurvePoints(nurbs_curve)
weights = rs.CurveWeights(nurbs_curve)
knots = rs.CurveKnots(nurbs_curve)
degree = rs.CurveDegree(nurbs_curve) (13.8 KB)

According to Rhino - What are NURBS?

Rhino uses knots = number_control_points + curve_degree - 1, since with the +1 definition, the first and last ones are not useful.

You script seems to do the right thing then.

Ok but why don’t Rhino NUBRS comply with the actual definition?

Thanks @dale ,

Interesting article. I understand now, however if one is trying to write import/export tool to/from Rhino will end up confused because all other modern tools use these extra knots.