This article discusses Michelle Rhee's style of leadership--as steely as the sound of her peekaboo high heels on a linoleum-tile hallway--which has angered much of Washington, D.C., and baffled the rest since she arrived as schools chancellor in June 2007. But it is also helping her gain control of a school system that has defied management for decades: that hasn't kept records, patched windows, met budgets, delivered books, returned phone calls, followed court orders, checked teachers' credentials, or, for years on end, opened school on schedule in the fall. Rhee has some tools that other school heads don't have. Congress gave her the power to impose a teacher-evaluation system without negotiating its terms with the union. The new evaluations, set to begin in the 2009-2010 school year, will include student test scores and five classroom observations of each teacher each year. And then there are some test-score gains, which Rhee is counting on to build public support for her plans and ease the doubts about her style. Two years after Rhee's arrival, scores on district-administered tests are up: 49 percent of elementary school students were reading at grade level, a 21-percentage-point jump in two years, according to test results released in July 2009. Among secondary-school students, 40 percent were at grade level in math, up 13 points. Rising proficiency levels should win Rhee new clout in the city's political circles, new respect among parents and civil groups, and more leverage to turn the troubled system around. (Contains 1 figure.)