From Ivy Halls to the Garden, Surprise Star Jolts the N.B.A.

New York’s newest basketball sensation spends most nights on a couch in a one-bedroom apartment on the Lower East Side. The housing choice is understandable once you get to know Jeremy Lin.

He is a Harvard graduate playing in the National Basketball Association. He is an Asian-American in a league devoid of them, which makes him doubly anomalous. No team drafted Lin in 2010. Two teams cut him in December, before the Knicks picked him up.

His contract, potentially worth nearly $800,000, was not even guaranteed until Tuesday afternoon. So for the past six weeks, Lin, 23, has been sleeping in his brother Josh’s living room, waiting for clarity and career security.

“He has his own couch,” Josh Lin, a New York University dental student, said cheerfully.

He should be able to reclaim his living room soon enough.

Jeremy Lin’s utterly distinctive, mostly transient N.B.A. existence has taken a rather sudden turn over the past few days.

On Saturday night, Lin came off the bench and powered the Knicks to a 99-92 victory over the Nets at Madison Square Garden, scoring a career-best 25 points with 7 assists. Two nights later, he made his first N.B.A. start and produced 28 points and 8 assists in a 99-88 win over the Utah Jazz.

Knicks fans now serenade Lin with chants of “Je-re-my!” and “M.V.P.!” while the franchise uses his likeness to sell tickets and teammates and coaches gush with praise.

With every game, every precision pass and every clever drive to the basket, Lin is raising expectations, altering the Knicks’ fate and redefining the word “unlikely.” On Twitter, fans and basketball pundits are using another term to describe the phenomenon: “Linsanity.”

Two weeks ago, the 6-foot-3 Lin was not even part of the Knicks’ point-guard rotation, despite their lack of talent at the position. He played sparingly in a few games, showing just enough promise to keep getting another look— a few more minutes, another quarter. But there was never any hint of what was to come.

With 25 points Saturday, Lin set the N.B.A. scoring record for a player from Harvard. For an encore, he became the first player in more than 30 years to record at least 28 points and 8 assists in his first N.B.A. start. The last to do so was Isiah Thomas, the Detroit Pistons’ Hall of Fame point guard, in October 1981.

“I don’t think anyone, including myself, saw this coming,” Lin said after the game Monday.

That is, essentially, the story of Lin’s career. He was cut in December by the Golden State Warriors, his hometown team, after one season in which he rarely left the bench. The Warriors were intrigued enough to sign him but not enough to keep him. The Houston Rockets gave Lin a quick look and cut him.

When the Knicks claimed Lin off waivers Dec. 27, he was fourth on the depth chart at point guard. Now he is No. 1, continuing a long pattern of low expectations and surprising results.

Lin received no college scholarship offers, despite leading his Palo Alto High School team to a 32-1 record and the California championship. At Harvard, he was twice named to the all-Ivy League first team and delivered a signature 30-point performance against 12th-ranked Connecticut.

At draft time, in June 2010, Lin was again overlooked. N.B.A. teams had their doubts — about his defense, about his jump shot, about his ability to keep up with the league’s elite athletes.

They were the kind of concerns scouts have every year about dozens of prospects, from all sorts of programs and all sorts of backgrounds. Yet there was no escaping Lin’s unusual pedigree and the subtle sense that he did not fit a profile.

Lin is the N.B.A.’s first American-born player of Taiwanese or Chinese descent and only the fourth Asian-American in league history. His parents, Shirley and Gie-Ming, who are engineers, emigrated from Taiwan to the United States in the 1970s.

“I think people are surprised, because people don’t know him, or maybe he’s a pioneer,” Shirley Lin said. “There’s not that many Harvard players, not that many Asian-Americans. He’s just kind of like underdog. But he works hard.”

The qualities that make Lin unique, and seemingly held him back, are now the qualities that make him a sensation. Knicks fans were clamoring for Lin before he threw his first pass at the Garden. They roar louder for his shifty layups in traffic than they do for Carmelo Anthony’s.

Lin is the proud underdog defying scouts, stunning opposing defenders and forcing reassessments with every daring burst into the lane. He is more than a novelty now, but also more than just an underrated player finding success.

Social networks lighted up Saturday night and again Monday with excited chatter about Lin, much of it from Asian-American fans who have been following him for years.

“It’s just a real point of pride, the success he is having,” said Carl Park, a 35-year-old graduate student in Chicago and a first-generation Korean-American.

Park grew up a Milwaukee Bucks fan, but he roots for Lin wherever he plays.

“It represents a step for the Asian-American community as it becomes part of American culture more broadly,” Park said.

To illustrate his point, Park posted a humorous “Timeline for what Asian-Americans get called in pickup basketball” on his Facebook page. In 1980, it was “Bruce” (as in Lee). In 1995, “Jackie Chan.” In 2000, “Yao,” for Yao Ming.

In 2012, “Jeremy.”

The first examples came from Park’s own experience as a recreational player. The last, he hopes to hear.

“It’s nice there’s been some progress that way,” Park said, “in that younger guys might actually get called the name of an actual basketball player.”

Yet the Lin phenomenon transcends race or nationality. He resonates with devout Christians, because he speaks openly of his faith, a sort of Taiwanese Tim Tebow. He taps into the passions of Harvard alumni, Ivy Leaguers, New Yorkers and anyone anywhere who loves an underdog.

“Jeremy Lin” was a top trending topic on Twitter on Sunday, in New York and in San Francisco. On Monday, he picked up nearly 10,000 followers on his account, @JLin7. On Tuesday, a Lin-themed rap appeared on YouTube.

No demographic seems to love him as much as Knicks fans, who are suddenly counting on Lin to revive their flagging season. The stars, Anthony and Amar’e Stoudemire, have struggled. The presumed starting point guard, Baron Davis, is recovering from a back injury. The Knicks have lost 15 of their first 25 games, dousing their championship hopes.

Another setback came Tuesday, when the Knicks announced that Anthony would miss up to two weeks because of a groin injury.

On Twitter, the fan response came swiftly: “As long as we have Jeremy Lin, we’ll be fine,” wrote @CareyWilbur.

It is perhaps too much to ask the undrafted player from Harvard to save the season. It seems more likely that Lin, who has a degree in economics, will ultimately settle into a more modest nightly role.

But the uncertainty is over. Lin has cemented himself as a credible N.B.A. player, not a novelty act. On Tuesday, his contract became guaranteed for the season. The Knicks are keeping him. It seems safe to go apartment hunting.

“I think he’s looking forward to it,” Josh Lin said.