Malcolm Gladwell, author of The Tipping Point, Blink and Outliers, wrote a 2008 article for the New Yorker magazine titled Most Likely to Succeed. It was about how difficult it is to predict who will turn out to be a really good teacher.
Apparently, really good teaching (defined by the amount of learning that happens) is a bit of a mystery and hinges on very subtle differences in how one conducts class and interacts with one's students. He compares it to how difficult it has been historically for NFL scouts to predict which great college quarterbacks will also succeed at the pro level.
We don't know either. But we DO know that if you start with high quality materials created by veteran teachers, you are already giving yourself a leg up. Due to our incentive model, quality is MUCH higher on TpT today than it was in 2006 when we first launched, therefore continuing to use TpT resources fosters a virtuous cycle that takes a bit of the mystery out of great teaching.
Teach and be well,