Well said, Patrick, regarding Mr. De Blasio’s dubious opposition to relying on tests to determine who is admitted to New York City’s elite high schools. I have no objection in principle to considering other indicia of talent besides test scores, but this should not be because of a desire to achieve more racial and ethnic “diversity,” and race and ethnicity should themselves of course not be factors considered. And I’m not sure that, as a practical matter, it makes sense to change the current system. No selection system is perfect, and one can argue that in theory there would be good things about taking into account more factors than just a student’s score on one test. But there are also many advantages with the current system that will be lost if it is changed: Its simplicity, objectivity, and transparency — great virtues indeed, and just imagine the never-ending fights among groups and parents and students once it is abandoned and a new system has to be fashioned and implemented. The perfect can be the enemy of the good.