Passed in 2010 with bipartisan support, Colorado’s Senate Bill 191 is a big law that includes a lot of different timelines. Frequent delays in the law’s implementation only add to the confusion. But despite all that messiness, the law is beginning to do its work.

At its core, SB 191 is a tenure reform law. Okay, okay, legal nerds, a “non-probationary status” reform law. Previously, Colorado teachers earned non-probationary status after three years of teaching. That status provides near-absolute “due process” job protections that could force school district leaders to navigate legal requirements all the way to the steps of the Colorado Supreme Court should they decide to fire a non-probationary teacher. Under SB 191, teachers earn non-probationary status after three years of effective teaching. As an important corollary, those same teachers can lose that status after two years of ineffective teaching.

We’ve discussed the ins and outs of these reforms at some length in the context of the union-led assault on legislative authority that is the Masters case, which deals with SB 191’s lesser-known mutual consent provision. We’ve also covered the Independence Institute’s arguments about why the union is way off base legally in that case. We won’t beat those dead policy horses this afternoon. Instead, we’ll talk about the fact that SB 191’s centerpiece component—the loss of non-probationary status for ineffective teachers—has come online.

SB 191’s annual performance evaluations began counting toward the earning or loss of non-probationary status in 2014-15. That means that some teachers have now had time to earn two consecutive ineffective ratings—and lose their non-probationary status as a result.

Sure enough, Chalkbeat reported last week that, based on a survey of large school districts in Colorado, 47 teachers in Denver Public Schools will lose their non-probationary status because of two years of ineffective evaluations. That’s about 2 percent of the non-probationary teachers in the district. Twenty-four teachers in Douglas County will also lose their status, as will 12 in Aurora. One Cherry Creek teacher will become probationary again. Surprisingly, not a single teacher in Jefferson County—a district with nearly 5,000 teachers—will lose non-probationary status.

You should note that despite scary statements by accountability opponents that conjure images of guillotines in school yards, the loss of non-probationary status does not necessarily mean that the affected teachers will lose their jobs. It simply means that district and school leadership have the flexibility to dismiss them should they determine that doing so would be in the best interests of students. If you like local control, you should love that flexibility. Personnel decisions are best made by school and district leaders.

Some of you may be surprised by the relatively low number of teachers who have been rated ineffective for two years in a row. The relatively unimpressive numbers are probably explained by the fact that evaluation reform, the other big part of SB 191’s changes, has a long way to go toward enabling real, meaningful differentiation of performance in the classroom. It is very, very hard to be rated ineffective two years in a row under most district evaluation systems today.

Critics of these reforms typically frame them as some sort of edu-policy Armageddon, arguing that thousands upon thousands of teachers will be unfairly rated ineffective. In fact, research indicates that while evaluation reform has moved the needle in the right direction, it hasn’t gotten us where we need to go just yet. We should be working toward further strengthening our accountability system and making it more meaningful, not scaling it back in favor of a return to the days of 99 percent effective ratings across the board.

One final note: We need to be careful about how we view and discuss the impacts of this critical piece of SB 191’s reforms. Given the incredible power of effective teaching, we should be proud that the reforms move us closer to a world in which every single student has an effective teacher. Removing ineffective teachers from the classroom is indisputably the right thing to do in a general sense.

On the other hand, we shouldn’t be in the streets celebrating the loss of jobs or turning this into a witch hunt. Instead, we should be relentlessly chasing clear, accurate data about how teachers are impacting their students, then using those data to move education forward. Remember, using evaluations to measure performance for the purpose of identifying and dismissing ineffective teachers is only part of the equation. The other part is making sure that we are also differentiating performance in a way that allows us to incentivize and reward great teaching.

All that said, I’m pleased to see that SB 191 is finally beginning to work as intended. It’s not always easy or pretty to do the right thing in education, but we’ve got to do it. Students deserve no less.