Twelve positions where the engine's move is decisively best and most humans
never consider it. Play your move on each. No feedback until the end, when your answers
place you on the rating staircase from the research.
Your move: …
Your blind spot
Bars: how often real players in each band found machine unique moves,
measured over ~850 positions per band. Your placement is a maximum likelihood fit of your
twelve answers against each position's difficulty curve, not a raw percentage, so finding
three hard ones beats finding three easy ones.
One caveat, since the whole project is built on stating them: these twelve are
drawn from the trainer's drill sets, which are easier than the machine unique pool at large
(the model puts a 1900 rated player at 11% on them versus 6.6% across all such positions).
Placement therefore runs generous. Read it as a rough band, not a rating.