In CS or IT area, some guys with MS degree have poorer skills

In CS or IT area, some guys with M.S degree have very poor skills than the guys with B.S degree. Last years, my company hired 4 new graduates (2 with B.S and two with M.S). We found 2 B.S guys are much-much better in handle their tasks than other 2 M.S guys because 2 M.S guys have their B.S from other majors not in CS or ECE. so they need a much longer time for trainning because their base in CS is poor