Dave Schumer jokes that he and his family go so tired of arguing with his son, Sam, that the high school senior had to take his verbal wrangling skills to the professional level.

Sam Schumer started debating at the end of his freshman year at Thomas Jefferson High School, and he hasn’t looked back. Now a senior, Schumer is the preeminent debater in Federal Way schools.

“He always liked to verbally joust with people in the family,” David Schumer, who is also a debate judge (but never when Sam debates), says of his son. “He can always hold his own.”

Schumer’s life seems almost entirely devoted to debate. He spent part of last summer at debate camp. Between competitions, preparation and coaching other students, he estimates he spends at least 40 hours per week outside of school working on debate. He wants to attend a college with a strong extracurricular debate program. In January, he’s off to the University of California at Los Angeles where he will represent Thomas Jefferson in a national debate tournament.

Schumer, 17, is the youngest of four. He got into debate partly because he wanted to do something different from his older siblings. He’s also dyslexic, which debate has helped him overcome, he said.

He was homeschooled when he was young, then attended Charles Wright Academy in Tacoma. He came to Thomas Jefferson, as his siblings before him did, to take part in the school’s International Baccalaureate program.

As a freshman, he first did speech — another aspect of debate that deals with presenting a topic rather than directly arguing it. By the end of the year, he had joined the debate team. He participated in debates with a partner, but has been solo since the end of his junior year.

“Debate is one step further because you’re held accountable for the logic behind it,” Schumer said.

On a recent day, Schumer was in Thomas Jefferson speech and debate teacher Andrew Buchan’s class. Around him were younger students practicing speeches and doing research. He prepares for debates by finding scholarly or newsy evidence to support an argument and writing briefs.

“You look at all the parts and find the weakest link — that’s the part where you want to attack,” he said.

He puts his win average at about 66 percent, meaning he typically wins four and loses two arguments at a given debate competition.

The trick about debate is that debaters have to argue both sides of an issue: Why prayer should, for example, be allowed in schools, and why it should not.

One of the most important skills he’s learned in debate is to be emotionally neutral toward the topic at hand.

“There’s a rule that it stops being an argument when it becomes emotional,” he said. “Staying calm is vital. If I know I don’t believe everything I say, it weakens my argument.”

He’s argued some heady topics (The National Forensics League decides debate topics): Whether illicit drug abuse should be treated as a public health or a criminal justice issue; the importance of social networking sites (the first topic he debated); and the issue of building a community center near Ground Zero in lower Manhattan (there was too much uproar over that topic, he said, and the league had to change it). The next topic is cyberbullying.

In his free time, Schumer likes doing physics. He likes breaking down the inner workings of formulas. He also plays soccer and Ultimate Frisbee. There’s no television at home, but he uses the Internet, and a favorite site is the seemingly infinite Wikipedia.

“He’s on Facebook,” David Schumer said. “But he’s also on The Economist and Foreign Policy.”

Schumer’s parents are both doctors. David Schumer jests that he worries his son might pursue a career as a lawyer. But Sam’s not so sure. He said he’d love to do something in politics, but in college he’ll probably study international relations. Pre-law is a fallback option, though Schumer doesn’t seem to like the restrictions of the courtroom.

“When you take (debate) into the real world,” he said, “everything changes.”

“We’re very proud of all his hard work,” David Schumer said. “If I ever need someone in my corner to negotiate, I’d get Sam.”