I'm assuming most everyone taking the SAT subject test is also taking AP tests. AP tests were significantly more rigorous than SAT subject tests and would have

I'm assuming most everyone taking the SAT subject test is also taking AP tests. AP tests were significantly more rigorous than SAT subject tests and would have provided more useful information to admissions. It took more prep to get a 5 on an AP Chemistry test vs a top score on the SAT subject test.