Many college bound seniors now commiting to their schools of choice were selected based on their S.A.T. scores. About half of US colleges use the grandaddy of standardized tests as a major screening factor. In 2005, complaints from colleges about the tests’ limitations in demonstrating writing and critical thinking skills led administrators to add an essay portion to the exam. The new format was designed to be harder to “game,” but at least one test prep company has found a way to trump the new S.A.T…and tens of thousands of students are paying big money to learn the winning strategies….in China.