Will Eliminating the Double Dipping Period Impact the Boston Cutoff?

The BAA announced two changes for registration for the 2027 Boston Marathon. The big headline was the downhill results index. The subtler change was the beginning of the qualifying period for the 2027 Boston Marathon – and the elimination of the double dipping period.

For the last several years, the start of the next qualifying period period has been September 1 and the close of the previous qualifying period has been after Labor Day. For example, the qualifying period for the 2026 Boston Marathon began on 9/1/2024 and the qualifying period for the 2025 Boston Marathon ended on 9/13/2024.

This effectively meant that there were typically one or two weekends in which the results of a race could be used to qualify for two successive Boston Marathons. If you ran the 2024 Erie Marathon, that result was good for both the 2025 and the 2026 Boston Marathon.

How Many Runners Qualified During the Double Dipping Period?

One part of this question is easy to answer. How many races took place in the double dipping period and how many runners qualified at these races?

The qualifying period for the 2026 Boston Marathon ended on Friday, September 12, 2025. Under normal circumstances, this would have meant that races from 9/1, 9/6, and 9/7 would have been in this double dipping period. There was also the odd Friday race on 9/12. From the large sample of races used with the Boston Marathon Cutoff Time Tracker, that included ten races with a combined total of about 4,000 finishers.

In past years, a handful of other races have been in this time period. The Kauai Marathon was on 8/31/2025, but previously it was in early September. The Tunnel Lite Marathon was on 9/14/2025, and last year it was a week earlier. REVEL Big Cottonwood was also on 9/14/2025, but two years ago it was a week earlier. REVEL White Mountains was also in the period at one point, but it’s now retired anyway. And the Air Force Marathon was on 9/20/2025, when it was previously on 9/1/2024.

In past years, these races could have added another 2,000 to 3,000 finishers in the double dipping period. But the trend over the last few years seems to have been for races to drift out of this period for one reason or another.

Collectively, these races produced approximately 1,200 qualifiers for the 2026 Boston Marathon. In past years, these races would also have produced the same 1,200 qualifiers for the 2027 Boston Marathon.

A couple races saw a significantly higher than usual percent of their finishers qualify – Erie, the two Last Chance races, and the Wicked Fast Marathon (previously Jack and Jill Downhill Poconos). Another few had relatively high rates of qualification: Georgina, Beantown, and Cascade Express. The remainder didn’t produce many qualifiers.

It is worth noting here, though, that two of these races will be subject to the new downhill results index: Mt. Nebo and Cascade Express. If they had been included, the total number of qualifiers eligible for the 2027 Boston Marathon would have been slightly lower.

Are These Races Likely to Produce Applicants?

A relevant question here is whether the people running these races are likely to actually apply to run the Boston Marathon – or whether they just happen to be qualifiers.

Over the summer, I analyzed the conversion rate of qualifiers to applicants from individual races for the 2024 Boston Marathon. While typical North American races had conversion rates of 30-40%, many international races had far lower conversion rates. And a small group of races had much higher conversion rates.

A few of these races were in that group of high conversion races:

• 70-75%: Jack and Jill Downhill Poconos and Last Chance BQ Grand Rapids
• 65-70%: Last Chance BQ Chicagoland, Beantown, Mt. Nebo, Cascade Express
• 60-65%: Erie Marathon
• 55-60%: Georgina Marathon

Holland Haven and Sackets Harbor didn’t produce enough applicants to be included in that analysis.

The actual conversion rate could vary from year to year, but I’d expect all of these races to have a generally high conversion rate. These 1,200 qualifiers could convert into 700 to 800 applicants.

It’s also worth noting here that this conversion rate is based on qualifiers from the September 2024 races who ran the 2025 Boston Marathon. We don’t know how likely these same qualifiers are to apply for the following Boston Marathon.

It could be the same. But I’d wager some of these runners were primarily focused on getting into the next Boston Marathon and won’t be as concerned with the following year. The conversion rates from a September 2025 race to the 2027 Boston Marathon is probably still higher than usual, but it might result in fewer than the 700-800 applicants that would be expected at the 2026 Boston Marathon.

Do These Runners Run Other Races?

Just because we eliminate this double dipping period, though, doesn’t mean that we’ll necessarily eliminate these runners as applicants to the 2027 Boston Marathon. It’s likely that a large percentage of these qualifiers end up running the 2026 Boston Marathon, and with a whole qualifying period ahead of them it’s quite likely that many of these runners will run at least one other marathon before September 2026.

Recently, I did a retrospective on the full dataset from the 2026 Boston Marathon qualifying period. One of the questions I looked at was how likely runners were to complete more than one race in the qualifying period.

Of all runners, about 91% only ran one race. Another 7% ran two races and a very small number ran more than two races.

When you focus on runners who met their qualifying time, it’s more likely that a runner completed more than one marathon. 78% of qualifiers only ran one marathon. 16% ran two races and almost 6% ran more than 2 races.

Now, let’s drill down to the 1,228 runners who qualified at one of these early September races. 604 – almost 50% – ran at least one other race this year. And 283 – almost 25% – ran at least two other races.

In other words, these runners are much more likely to be multiple marathoners than regular runners. There are likely relatively few of these runners who planned on skating through the next 12 months without running another race … and then using a qualifying time from the 2025 Erie Marathon to apply to the 2027 Boston Marathon.

So What’s the Bottom Line on Double Dipping Races?

Eliminating these races from the qualifying period for the 2027 Boston Marathon will reduce the number of qualifiers and eligible applicants. But there’s a serious question of how meaningful that reduction will be.

The highest possible estimate would be about 700 to 800 fewer applicants. This is based on the number of qualifiers at this year’s races (~1,200) and the average conversion rate at the 2025 Boston Marathon (~60%).

However, it’s likely that the conversion rate from a September 2025 race to the 2027 Boston Marathon is lower. It’s also likely that a significant number of these applicants will run at least one more marathon in the next twelve months.

The actual numbers would be hard to pin down. But for sake of argument, let’s say that a third of these qualifiers run and qualify at an additional race and that the actual conversion rate is 50% instead of 60%. That would mean about 800 qualifiers were eliminated – equivalent to 400 applicants.

In a broader sense, this change will likely reduce the number of applicants by a few hundred compared to last year. Keeping everything else constant, that’s equivalent to 10, maybe 15 seconds on the cutoff time. A small but meaningful nudge downwards.