Also just because a parent is opposite does not guarantee they will do a bad job of parenting.
I felt that I was opposite from my middle ISTP son in that I was always very serious, and he is the epitome of fun. I loved school and learning; he hates it. I mean this in no small way. He is the opposite of everything I expected, and the way I wanted him to behave. I had an extremely hard time loving him and accepting him, so determining what "opposite" is might be difficult as well.
Instead of "punishing my son for who he is" - which was incredibly tempting - I chose to learn about his temperament and why he was behaving the way he was. It was very hard for me, but I learned to appreciate him for the way he was.
MBTI is what helped me understand my kids and myself. I used the books, Do What You Are and Nurture By Nature by Paul Tieger and Barbara Barron.
These give positive assessments of the types, much more positive than those many people here seem to have been exposed to, and helped me see the positive qualities my son did have.
It was hard for me to not try to squeeze my son into my mold, but I did the right thing, and I think other parents can, too.