Boston's 2027 Downhill Course Adjustment, Explained

Published July 5, 2026 · Estimates, updated each registration cycle

For the 2027 race the Boston Athletic Association introduced an adjustment for qualifying times set on courses with a large net elevation drop. Steep point-to-point downhill marathons produce faster times that do not reflect the same effort as a flat or rolling course, and the BAA now accounts for that.

What it does

In short, part of the advantage from a steeply net-downhill course is discounted when your time is assessed, so a time set on such a course is treated as slightly slower than the clock shows. The exact treatment depends on the course's net drop. If you qualified on a flat or rolling course, the rule does not affect you.

Why it matters for the cutoff

A meaningful share of fast BQs come from a small number of downhill courses. Discounting those times can thin the fast end of the applicant pool, which could lower the cutoff. The effect is new and untested, which is one reason the 2027 prediction carries a wide range.

This tool does not yet model the adjustment, so if you qualified on a steep downhill course, treat your odds in the predictor as optimistic.