The problem we're discussing is how does one determine who the "best" teachers are? Gates did not propose a solution to this problem. I submit that, being a government school system, such a solution will involve a bureaucratic rule that will inevitably be gamed.
Note that the current system of determining the best as being a bureaucratic rule-based combination of seniority and educational level is a recognized failure. I guarantee you that all the alternative rules proposed in this thread can be easily gamed as well.
This is in spite of the fact that anyone working in a school (including the students) knows who the best and worst teachers are, and don't need any rule to tell them.
Note that the current system of determining the best as being a bureaucratic rule-based combination of seniority and educational level is a recognized failure. I guarantee you that all the alternative rules proposed in this thread can be easily gamed as well.
This is in spite of the fact that anyone working in a school (including the students) knows who the best and worst teachers are, and don't need any rule to tell them.