Frenzied study for the national college entrance examinations is over for the year, and Chinese applicants to US universities have received their letters of rejection or admission. One exasperated student at Shanghai High School reported that one major topic on college chat sites has been why students get rejected by US schools. He was accepted by elite, Ivy League schools, but not by MIT, his first choice. "Many students wonder why they were rejected even though they had very high grades and excellent test scores," he told me.

Well, the following illustrates the essential difference between the Chinese and American admissions processes.

When I was at Boston College, I went to Princeton University to visit my older brother, Bob. On a Saturday late in October, we went with one of his roommates, David, to the Princeton-Rutgers football game. At halftime, the Princeton marching band took the field to entertain us. That band is famous, even notorious, for its excellence, its high degree of musicality and its playful antics.

During halftime, David told us the following. His lady friend worked in the admissions office. Admissions representatives had prepared a preliminary review list of students who might receive either a letter of admission or a letter of rejection. But then the musical director of the marching band came into the office. He told the admissions staff: "I need a trombone player."

His first trombone player was graduating the next year. And of course the Princeton marching band had to maintain its standard of excellence. So the admissions officers stopped discussing admission or rejection and went back through all of their applications to try to find a trombone player whose GPA and SAT scores met the minimum requirements. The trombone player would bump another applicant, and thus potentially other applicants, from the list.

Readers will understand what this means: Even if you are qualified for admission to a top school, you might be rejected for seemingly arbitrary reasons.

Shanghai students and their parents must deal with this fact: A high GPA and excellent test scores are crucial, but they do not ensure admission into US schools. The truth is that admission to the best schools is a game of chance. High GPA and test scores are absolutely necessary. But they only get you in the door. There are many other variables that US admissions officers consider, such as extracurricular activities, letters of recommendation and application essays. Students also might want to raise bees. Or study the trombone.

Shanghai parents find these facts almost unbelievable. One Shanghai client and her husband looked at me in disbelief when I explained the situation. Their son, Terry, was a student at Shanghai United International School. "You are saying that my son can achieve the highest scores in his school and still be rejected by top 10 schools?" the mother asked.

I had to answer that other variables are even more important.

The father just could not believe that. "What could be more important than good grades?" he asked.

I explained that all applicants to top schools are students with outstanding GPAs and test scores, but their scores alone do not differentiate them from other students. Thus, US schools look at other variables to find exceptional students.

The mother and father did not believe me until I showed them the Stanford University application evaluation criteria: curriculum, teacher evaluations, essays and extracurricular activities. It doesn't mention a high GPA, or excellent TOEFL, SAT or other test scores because they are assumed and expected.

Suddenly they heard the Princeton trombone. I hope all Shanghai students and their parents hear it, sooner rather than later.

The author has taught, tutored, and offered college advice in Shanghai for 10 years.