Equality of opportunity is a bit more complicated. Each of us does not have the same opportunities as another. There are MANY factors that go into the opportunities that one can utilize. Family of origin, genetics, intellect, physical health, place of birth, psychological health, all contribute to the level that one could possibly attain. Now, certainly one can overcome some of these struggles, but they still would create a disparity in the opportunities available.
Equality of opportunity can also be affected by societal rules and laws. For example, currently in the US, gays do not have the opportunity to get married. This is a societally created deficit and prevents equality of opportunity in this area. Affirmative action. This is a tricky one. On one side, using affirmative action creates an unequal opportunity situation. On the other, since it is not guaranteed that racism will never prevent one from an opportunity, there can certainly be some inequality by NOT having it.
Ultimately, equality of opportunity is not black or white. There are many subtitles that effect the concept. Since true equality of opportunity cannot be attained, the best we can hope for is some modifications to get it as close as possible.