Subsequent research largely confirmed his findings, and in the process many orthodoxies of education policy were called into question. In particular, studies indicated that the traditional measures of a teacher's quality -- such as years of experience, credentials and education -- have little bearing on his or her effectiveness.
To challenge students at his wealthy schools, Grier pushed principals to focus on growth rather than hitting fixed scores. He used the data to assign teachers to students who matched their strengths. He denied tenure to at least four teachers whose students did not show growth for several years, and reassigned some low-performing principals while encouraging others to retire.
At his next job in Guilford County, N.C., Grier hired Sanders to improve on the district's existing value-added program.
The goal of the program, dubbed Mission Possible, was to attract effective teachers to low-performing schools. To do this, Grier offered highly effective teachers up to $10,000 to relocate. They got up to $4,000 more if students' test scores rose.
Many educators protested the plan, but, with no collective bargaining in North Carolina, the board approved Mission Possible in 2006.
By 2007, teacher turnover at some of the area's lowest-performing schools had been cut by almost half, according to a recent independent study. But the program hasn't significantly changed student achievement -- at least, not yet.
"It's a mixed bag," said board member Alan Duncan. The real test, he said, will be a few years from now, when the board expects the changes to show up in test scores.
North Carolina has since adopted value-added statewide.
Grier said he knew that Mission Possible wasn't possible in San Diego. "The board made it clear they were not interested in a merit-pay program," he said.
Instead, Grier wanted to find out how the district's high-performing teachers were distributed. He suspected that many were clustered north of Interstate 8, in the wealthier part of the city.
He lured Sanders, now with a for-profit data analysis company, to visit San Diego with the promise of golf at Torrey Pines. The statistician's presentation persuaded the school board to approve a one-year, $80,000 contract with Sanders' company -- but limited its use to identifying students in need of extra help.
Union officials decried the move, saying the money would have been better spent hiring another teacher. They suspected Grier was trying to move the district toward merit pay. "We knew his history," said union President Camille Zombro.
She and other union members interrupted a school board meeting in June to present the board with a petition complaining about Grier's top-down management style and calling for his removal.
"He looked good in a suit, but he wasn't willing to collaborate," Zombro said.
Relations with the administrators union also soured when Grier tried to use value-added scores as a component of principal evaluation, a plan that was eventually rejected.
The board did not renew Sanders' contract this fall and never made public the results of his analysis.
Grier took over as Houston's superintendent in September. Reached by telephone recently, he seemed invigorated.
"They do things differently out here," he said. "It's a breath of fresh air."