"It is not like the College Bowl," Tally, 55, said, in which the students ring a buzzer to answer questions.
The super quiz topic changes every year. This year the topic is the history and future of the Internet. Last year it was philosophy, psychology and religion.
The competition begins with a series of multiple choice exams on each topic, followed by the prepared speech on a topic of the student's choice and the impromptu speech. Impromptu speech topics are chosen from three options listed on pieces of paper drawn at random. Interview topics may revolve around answers to questions on a form filled out by each student.
Tally said he encourages the team members to expand on their verbal answers and to look the interviewers in the eye to determine the reaction to their answers. During the whole process Tally is not allowed in the same room as the students.
"I'm locked in a closet," he said.
Students are given 50 minutes to write the essay on a topic of their choice from a list of four.
Scores for each event range between zero and 1,000.
Each decathlon team has three students from each of three grade-point averages: 3.75 and above, 3.0 to 3.74 and under 3.0. The GPAs correspond to A-, B- and C-level students. The top two scores in each group are counted toward the team's overall effort.
Tally said the success of a student has less to do with his GPA than with the student's attention span.
Hanna Shim, a 15-year-old sophomore, said the team helps build responsibility and punctuality, both of which help with future careers.
"It's fun and different," she said, adding this is her first year competing, and that she is an alternate A student whose competition scores only count if for some reason someone else's do not.
Jeremy Pachter, a 16-year-old junior, also is new to the team this year. He said he joined because he needs the five credits.
"I failed a couple of classes last semester," he said.
Pachter is in the C grade group and finished this year's county competition only 200 points off the high score.
"It's very, very, very, very difficult," he said.
Emma Jones, principal at Central, praised Tally for his ability to get the students to focus on the task of getting ready for the decathlon, especially when in San Diego.
"He's so dedicated with the kids," she said.
Jones said she's known Tally since he arrived at Central and that he was an assistant softball coach with her in 1977.
"I know him in many ways," she said. "He's just a great guy."
Tally credits the school's long-running success to the effort put in by Central's students. Students typically stay after school to work together, and once a year they head over to Pacific Beach for several days and study together.
"It's kind of cruel and unusual punishment. You take them to the beach and make them stay inside and study," Tally said.
They don't only study, however; they get time to enjoy the beach and go out for dinner.
Tally has been teaching in the same classroom at Central since he arrived at Central.
"My whole life," he said.
He teaches four Gifted and Talented Education English courses besides Academic Decathlon.
He said his wife, Sue, who works in the Imperial County Office of Education's child development services, travels to the state competition and San Diego with him and they've taken their now-grown children as well.
"She's the co-coach," he said.
The couple have a daughter in law school and a son majoring in engineering at the University of California, Berkeley. They had no interest in competing in the decathlon, Tally said.
Coaching Academic Decathlon leaves little time for outside interests. Tally said he watches no television other than San Diego Chargers and Padres games. He gets all the reading he can take just in coaching the team, though he does manage to read one novel — for the competition — each year and do crossword puzzles.
This year, true to form, Central won the local competition and will move on to the state finals March 22-23 in Modesto. Whichever school wins moves on to the national level.