Two 40-year-old men both want to run Boston in 2027. Both need 3:05:00. One qualifies at a flat local marathon. The other qualifies at St. George, dropping 2,560 feet from start to finish.
Same bracket, same clock time on the day — but the St. George runner's qualifying time now gets 5 minutes added before the BAA compares it to the standard. To actually get in, he needs to run 3:00:00 for real. That's not the same performance anymore. It's not even close on the sport's own measuring stick.
I wrote about how the flat Boston standard age-grades unevenly by bracket last week. The BAA's new net-downhill index changes that math again, and this time it changes it by course, not just by age.
What the downhill index actually does
It adds minutes to a qualifying time before the BAA compares it to the standard, based on how much the course drops from start to finish. The BAA defines net-downhill as "the difference in elevation between the start and finish points of an event," and first announced the rule in June 2025 for the 2027 qualifying cycle (baa.org, 2026-and-2027-registration-updates).
The tiers, as published on the BAA's own qualifying page:
| Net-downhill | Time added | Effect |
|---|---|---|
| Under 1,500 ft | None | Qualifies as run |
| 1,500-2,999 ft | +5:00 | Time indexed before comparison |
| 3,000-5,999 ft | +10:00 | Time indexed before comparison |
| 6,000 ft or more | — | Not eligible as a qualifier |
(baa.org/races/boston-marathon/qualify, retrieved 2026-08-26.)
So a runner who crosses the line in 2:52:40 on a course with a 2,200-foot drop gets that result treated as 2:57:40 for qualifying purposes. The clock at the finish line never changes. What changes is the number the BAA measures against its bracket standard.
This post runs that indexed time through the same age-graded percentage method as the flat-standard post. Take the marathon age-standard time for the runner's exact age, divide by the time the BAA is actually judging, and multiply by 100.
The same bracket, a very different bar
Take the men's 40-44 bracket again, the same one the flat-standard post opened with. The Alan Jones 2025 age standard at 40 is 2:03:15.
| Course type | Time BAA judges | Age grade |
|---|---|---|
| Flat (no drop) | 3:05:00 | 66.6% |
| +5:00 course | 3:00:00 raw needed | 68.5% |
| +10:00 course | 2:55:00 raw needed | 70.4% |
The flat standard and the +10:00 standard are separated by nearly 4 points of age grade for the exact same bracket, the exact same age, the exact same nominal "3:05:00 qualifies you" rule. A runner on a steep enough course has to run a materially better age-graded race than a runner on a flat one, to clear what BAA still calls the same bar.
How far does the bar move, by bracket?
It moves everywhere, and by more at the young end of the masters range than the old end. Take every men's bracket at its youngest, hardest-hit age and compare the flat age grade to both penalty tiers.
| Bracket | Age | Flat | +5:00 | +10:00 |
|---|---|---|---|---|
| 18-34 | 18 | 71.2% | 73.3% | 75.5% |
| 35-39 | 35 | 67.0% | 68.9% | 70.9% |
| 40-44 | 40 | 66.6% | 68.5% | 70.4% |
| 45-49 | 45 | 66.0% | 67.7% | 69.5% |
| 50-54 | 50 | 67.3% | 69.0% | 70.8% |
| 55-59 | 55 | 67.1% | 68.8% | 70.5% |
| 60-64 | 60 | 64.4% | 65.8% | 67.3% |
| 65-69 | 65 | 63.6% | 65.0% | 66.4% |
| 70-74 | 70 | 63.3% | 64.6% | 65.9% |
| 75-79 | 75 | 63.9% | 65.1% | 66.4% |
Under the flat standard, almost none of these brackets reached 70% — the line RaceRecords' own convention calls local class. Under the +10:00 tier, five of ten do: 18-34, 35-39, 40-44, 50-54, and 55-59 all clear it, most by half a point or more.
The gap between flat and +10:00 also isn't constant. It runs +4.3 points at 18-34 and narrows to +2.5 by 75-79. Five-year brackets already flatten a continuous curve into a step — a flat number of minutes on top of a flat time does the same thing again, and the two flattenings don't cancel out. They stack unevenly across age.
Two real downhill courses, run through it
The rule names elevation thresholds, not race names. But two real, well-known Boston-qualifying courses fall cleanly into the two penalty tiers.
St. George Marathon starts at 5,240 ft in Utah's Pine Valley Mountains and finishes at 2,680 ft in downtown St. George — a net drop of 2,560 ft (Wikipedia), which matches the race organizer's own description of "nearly 2,600 feet" (sgcityutah.gov). That lands inside the 1,500-2,999 ft band, a +5:00 penalty. A 40-year-old man who runs 3:00:00 there needs the whole 5 minutes of margin just to still clear 3:05:00 once indexed — and that 3:00:00 age-grades to 68.5%, not the 66.6% a flat-course 3:05:00 would earn.
REVEL Big Cottonwood Marathon starts at 9,625 ft in Big Cottonwood Canyon and finishes at 4,377 ft in Salt Lake County — a net drop of roughly 5,248 ft (findmymarathon.com). That sits inside the 3,000-5,999 ft band, a +10:00 penalty — the steeper tier this post's chart shows pushing most brackets past 70%.
Both are marketed partly on being fast. Under the 2027 rules, "fast" and "qualifies easily" stop being quite the same claim.
Does this finally push Boston past 70%?
For downhill qualifiers, mostly yes. The earlier post on this bracket found that even at its toughest, the flat Boston standard rarely reached 70% age-graded — RaceRecords' own line for local-class running. Among the brackets with an upper edge, only two cases cleared it: an 18-year-old man at 71.2% and a 79-year-old woman at 74.5%. The open-ended 80+ bracket clears it comfortably, as that post noted.
The +10:00 tier changes that finding for anyone qualifying on a steep enough course. Five of ten men's brackets now clear 70% at their hardest-hit age, and the +5:00 tier alone pushes several bracket edges past it too (18-34 at 73.3%, 40-44's oldest age at 70.9%, 50-54's oldest age at 71.6%).
That doesn't make Boston's standard suddenly demanding across the board — a flat-course qualifier's bar hasn't moved at all. It does mean the earlier post's conclusion — "qualifying and running a strong age-graded race are related, not identical, tests" — now depends partly on which course you picked, not just which age you are. Several of these numbers now sit close to the 80% national-class targets too, though none of the tiers computed here actually reach that line.
This post works the men's brackets only, the same way the flat-standard analysis led with them. The BAA applies the same net-downhill tiers to the women's standards on the same page, and the arithmetic carries over directly — a women's bracket standard minus 5 or 10 minutes, divided into the Alan Jones 2025 age-standard time, the same way it's computed above.
What this means if you're chasing a downhill BQ
Check your target course's net-downhill figure before you bank a qualifying attempt on it. A 2,000-foot drop and a 5,500-foot drop both used to earn identical credit toward Boston. From 2027 they don't, and the difference isn't small: it's the gap between running 5 extra minutes of margin and running 10.
It also means the downhill-course advantage that made races like St. George and Big Cottonwood popular BQ targets is now partly clawed back by the same body that sets the standard. Not eliminated — a well-run downhill race is still an advantage even after indexing — but reduced, and reduced by more the steeper the course.
If your qualifying plan already assumed a flat or rolling course, none of this changes anything for you. The index only prices in the courses it was built to catch.
Sources and what they said
- Boston Athletic Association, "Qualify for the Boston Marathon" — the full 2027 qualifying standards table by age and sex, and the net-downhill index tiers (1,500-2,999 ft = +5:00, 3,000-5,999 ft = +10:00, 6,000+ ft ineligible), published on the same page as the standards themselves. Retrieved 2026-08-26. https://www.baa.org/races/boston-marathon/qualify
- Boston Athletic Association, "2026 and 2027 Registration Updates for the Boston Marathon" — the original June 2025 announcement of the net-downhill index, its definition of net-downhill, and the BAA's statement that the tiers are "in place for at least the next two years". Retrieved 2026-08-26. https://www.baa.org/news/2026-and-2027-registration-updates-boston-marathon-presented-bank-america/
- Boston Athletic Association, "Registration Updates and Information Announced for 2027 Boston Marathon" — the 2027 registration week (September 14-18, 2026) and applicant notification timeline. Retrieved 2026-08-26. https://www.baa.org/news/registration-updates-and-information-announced-for-2027-boston-marathon-presented-by-bank-of-america/
- Alan Jones, Age-Grade Tables, 2025 road edition — the marathon age-standard times (MaleRoadStd2025.xlsx, AgeStdHMS sheet) used for every age-grade figure in this post, computed directly from the source file rather than read off a calculator. Retrieved 2026-08-26. https://github.com/AlanLyttonJones/Age-Grade-Tables
- Wikipedia, "St. George Marathon" — start elevation (5,240 ft) and finish elevation (2,680 ft) used to compute the course's net-downhill figure. Retrieved 2026-08-26. https://en.wikipedia.org/wiki/St._George_Marathon
- findmymarathon.com, "REVEL Big Cottonwood Marathon Elevation Information" — start elevation (9,625 ft) and finish elevation (4,377 ft) used to compute the course's net-downhill figure. Retrieved 2026-08-26. https://findmymarathon.com/elevation.php?elevation=REVEL+Big+Cottonwood+Marathon
No figure in this post was read off a third-party BQ-index calculator. Every age grade here comes from the BAA's own published penalty tiers divided into the Alan Jones 2025 age-standard time for that exact age.