Current PI (Performance Index) blends how the runner is going right now with
their career score: about 70% their most recent section and
30% their career iTRA PI. It updates every section and is
the level we use to predict the next one. (Before the first section it's
just the career iTRA PI; a runner with no career PI uses their latest
section alone.)
Section PI is what that one section implies on its own —
that single leg's pace against the reference, ignoring the rest of the race.
Read either against the runner's career iTRA PI: a higher number means they
ran harder than their score predicts; lower means slower (tired, or pacing
on purpose).
Expected at is our predicted arrival at the next aid
station: its terrain-adjusted (“equivalent”) distance run at the
Current PI's pace, plus a small allowance for fade because runners slow
over a long day. It refreshes each time a section finishes.