first of all.....i think that scyther is better than pinsir


anywayz...... lets start the battle

      IF PINSIR GOES FIRST

1 grass 60HP pinsir: attach 1 grass energy

1 grass 70HP scyther: attach 1 grass energy
              use swords dance

2 grass 60HP pinsir: attach 1 grass energy
                                  iron grip
                                50/50 chance of paralysis
                                 pinsir already won the coin toss so chances
are you are gonna get a tails

2 grass 50HP scyther: attach 1 grass energy   / attach 1 double colorless
energy
                         use swords dance          / use slash = pinsir faints

3 grass 60HP pinsir: attach 1 grass energy    / attach 1 double colorless
energy
                     use iron grip                   / use guillotine =
scyther faints 
                     scyther is paralyzed      /scyther faints 

3 grass 30HP scyther: attach 1 grass energy
                                      scyther is paralyzed 
 
4 grass 60HP pinsir: attach 1 grass energy
                     use guillotine
                     scyther faints  

     IF SCYTHER GOES FIRST

1 grass 70HP scyther: attach 1 grass energy
                         use swords dance

1 grass 60HP pinsir: attach 1 grass energy

2 grass 70HP scyther: attach 1 grass energy
                         use swords dance

2 grass 60HP pinsir: attach 1 grass energy
                     iron grip
                   50/50 chance of paralysis
                     scyther already won the coin toss so chances are you are
gonna get a heads

3 grass 50HP scyther: attach 1 grass energy
                                      scyther is paralyzed

3 grass 60HP pinsir: attach 1 grass energy
                     iron grip

3 grass 30HP scyther: slash

4 grass 30HP pinsir: attach 1 grass energy
                                  guillotine = scyther faints

so pinsir is definitely to better if they face eachother.
but in real battle, scyther is better.
the only reason pinsir won was because it paralyzed scyther
only some water and grass and colorless pokemon can do that.
making two pokemon battle hardly proves anything.
in the long run, scyther really truly is better.