0.0  0.0
  0.0  0.0
  0.0  1.0
  0.1  0.9
  0.2  0.8
  0.3  0.7
  0.4  0.6
  0.5  0.5
  0.6  0.4
  0.7  0.3
  0.8  0.2
  0.9  0.1
  1.0  0.0
  1.0  1.0
  1.0  1.0