Because what I hadn’t known — this is my first time grading this exam — was that it doesn’t matter how well you write, or what you think. Here we spent the year reading books and emulating great writers, constructing leads that would make everyone want to read our work, developing a voice that would engage our readers, using our imaginations to make our work unique and important, and, most of all, being honest. And none of that matters. All that matters, it turns out, is that you cite two facts from the reading material in every answer. That gives you full credit. You can compose a “Gettysburg Address” for the 21st century on the apportioned lines in your test booklet, but if you’ve provided only one fact from the text you read in preparation, then you will earn only half credit. In your constructed response — no matter how well written, correct, intelligent, noble, beautiful, and meaningful it is —if you’ve not collected any specific facts from the provided readings (even if you happen to know more information about the chosen topic than the readings provide), then you will get a zero.
The tests won't change much; the difference will be that under the Common Core there will be no argument for doing anything more.