I agree re. Flight paths. At our school they use a formula involving SATs results, number of previous schools attended, deprivation index, etc., to predict a level for GCSEs - all GCSEs, which they don't reveal to parents. Then they step that level back through the span of time at the school, so they derive a 'target level' for each year, which is revealed to parents.
So my DD2 has a "target level" of 0.5 - 2 for all her subjects this year. Using the information we've had, they are expecting her to get GCSEs of level 4-6. Other pupils, who are expected to get 9s in their GCSEs will have much higher target levels.
But it's a nonsense. In her first term, DD2 is getting level 2 or beyond in some subjects, which means she'll well overshoot her targets. In other subjects, she's on 0.5 which means she'll meet target, at least, but I know she's struggling with them.
Learning isn't linear. Children's past shouldn't dictate their future. If a teacher sees she's meeting target in term one, are they going to stop bothering with her? I hope not.