(Bloomberg) -- It took Stan Kelman three years ofmonitoring and tinkering to muscle his wife’s credit score to a perfect850. “It’s a personal achievement,” says the 44-year-oldbusiness analyst and data scientist. “I’m very proud ofit.”

Anna, his wife, let him direct the strategy for managing heraccounts—whether to apply for new credit, when to ask forhigher limits, how much of those limits to draw on. Herhusband, a self-described credit card-obsessive, was alsoworking on his own record. Six months ago, when some big creditblemishes finally dropped off his report, his score reached ashigh as 842. Within a year, Kelman thinks he can reach 850,too.

Some 200 million U.S. consumers have FICO credit scores, whilejust under 3 million, or about 1.4%, have perfect 850s.That’s according to Fair Isaac Corp., the company behind the28-year-old scoring model used by lenders to predict whetheryou will pay back a loan. But over the years the numberhas become much more than that—it’s now an American totem ofsuccess or failure, hope or despair, security or risk. While thereare competing models, almost anyone with a credit card knows that anumber typically ranging between 300 and 850 holds huge swayover their financial life.