Gary Petrazzuolo is a Northern Virginia biochemist who understands complicated statistics. His youngest daughter attends Falls Church High School in Fairfax County. He is angry that resources for that school might be drained away by a proposed public charter school to be called the Fairfax Leadership Academy. And so he sends me detailed critiques of the charter plans.Petrazzuolo is unhappy with a piece in The Post in which former Fairfax school board member Kris Amundson said many low-income minorities in that area are not performing well. Petrazzuolo asks why Amundson cited third grade test results, since the new charter is only for seventh through 12th graders. He discovered that existing schools in the area were doing relatively well raising achievement for minority children. It is white children who need help, according to his data. Affluent suburbs like Fairfax don’t like charter schools, which are tax-supported but not bound by district rules and practices. Petrazzuolo, part of a group called United Parents to Renovate Our Academic Resources (UPROAR), says it would be better to spend the money that would go to the new charter on improving existing regular schools.Good school districts like Fairfax don’t see a need for charters for the same reason I don’t think you need to read any education columnists other than me. Fairfax school leaders and I can be blind to the creative power of competition.