If you are interested in running the Boston Marathon, then you know that you need to meet a qualifying time to get in. This is colloquially known as your BQ.
And if you’ve been interested in this topic lately, you know that when too many people qualify and apply to run the Boston Marathon, they use a cutoff time to reduce the field of potential applicants.
Last year, the Boston Marathon saw a record number of qualified applicants, and this led to a steep cutoff time of 5:29. You had to be more than five minutes below your BQ in order to actually get in.
Since then, there’s been plenty of speculation about what this year’s cutoff would be.
Was last year a fluke and things would return to normal? Or will there be more qualifiers this year than ever before – leading to an even steeper cutoff time?
I set about collecting an enormous dataset to help answer these questions and predict the cutoff time for the 2025 Boston Marathon.
I published the full analysis in Runner’s Life on Medium. If you’re not a Medium subscriber, you can use this form to receive a special link to get you behind Medium’s paywall to read that analysis.
Or keep reading below if you just want the highlights.
An Overview of the Dataset
To answer this question, I needed to be able to quantify how many people qualified for the 2024 Boston Marathon and how many qualified for the 2025 Boston Marathon.
I assembled a dataset that includes individual results from about 250 races. For the most part, this dataset was limited to the United States and Canada, but I did also include the London Marathon.
In total, the dataset includes approximately 500,000 individual results in each qualifying period. These individual results were scraped from publicly available sources, including Athlinks, Marathon Guide, and individual race websites.
If you’re technically proficient, you can work with the dataset yourself directly on Kaggle.
So What’s the Predicted Cutoff Time?
Let’s cut to the chase, shall we?
The predicted cutoff time is 7:03. Give or take a minute. If I was hedging my bets, I’d guess that it’s more likely to be above that point than below it.
In short, there were more finishers across the 250 races in this qualifying period. That led to a significant increase in the total number of qualified runners.
Note that for the purposes of calculating qualified runners, I did the best I could to match multiple results per runner and only keep the fastest time. So the numbers below represent individual runners who have qualified – not individual finish times below the qualifying time.
The visual below summarizes the relevant information. It plots the number of qualified runners against the number of seconds that their qualifying time was below their BQ.
The blue line shows the number of qualified runners in the 2024 qualifying period.
At the right end of the visual, there were 46,621 qualified runners that finished at a time equal to or less than their BQ. If you follow the line to the left to the first vertical line, this indicates the number of qualified runners at the actual cutoff time last year: 33,777.
The purple line above shows the number of qualified runners in the 2025 qualifying period.
If we follow the horizontal line further to the left, it intersects the purple line at approximately -423 seconds – or 7:03. This would reduce the pool of qualified runners to 33,761.
The Rest of the Story
Earlier in the year, I read a similar prediction. And the response from some runners was disbelief.
The weather at the 2024 Boston Marathon had been warm and the results were abnormally slow. This race is the single greatest source of BQ’s each year, so if thousands fewer runners qualified at Boston … shouldn’t that reduce the cutoff time?
The problem with this is that it takes an isolated piece of evidence out of context.
True, there were a few races that yielded fewer qualifiers. At the top of the list was Boston. Beneath that was London, because both the 2022 and 2023 London Marathons were in the qualifying window last year. And third on the list was the Twin Cities Marathon – which was cancelled due to extreme heat.
But on the flip side, many races yielded more qualifiers this year. The Chicago Marathon yielded an additional 3,000 qualifiers and New York City yielded an additional 1,700. I could go down the list, but the short answer is that these increases more than compensated for the decreases at a handful of races.
This was driven in no small part by an increase in the total number of finishers. The 2025 qualifying period lost 40,000 finishers from the 2022 London Marathon and 7,000 from Twin Cities. But despite these losses, the overall field grew by about 25,000 finishers.
In late 2022 and early 2023 – the time period of the 2024 qualifying period – races were still rebounding from COVID. And across the board, field sizes grew from one year to the next.
And it’s just that simple: more runners, more qualifiers.
See the Medium article for more visuals highlighting the races that gained or lost qualifiers and whose fields grew or shrank.
Again, if you’re not a Medium subscriber, you can use this form to receive a special link to get you behind Medium’s paywall to read that analysis.
What’s Your Take – Will the Cutoff Remain High?
There is, of course, some uncertainty here.
We don’t know how many of these qualified runners will actually apply to run Boston. And there are some other international races not included in this sample set.
But I think 7 minutes is a reasonable estimate. I’d be shocked if it was below five minutes. At the same time, although it might be slightly higher, I’d be shocked if it was above 10 minutes.
What do you think – will it be higher or lower?
But the real question is what happens next.
Assuming we have a high cutoff this year, will the BAA leave the qualifying times alone – ensuring future years with significant cutoff times? Or will they make those qualifying times stricter in an attempt to limit the depth of the cutoff?
If true then maybe Boston should go back to restricting the course qualifications; ie loop courses or min max elevation gains and losses.
There are a lot of downhill marathons allowing runners easier BQ’s which would reduce BQ’s if they were eliminated or rerouted to meet this ‘new’ standard.
Easier said than done. Define a downhill marathon in terms that don’t target a specific race AND doesn’t include Boston, which is also a downhill race. Go ahead, I’ll wait. I bet you can’t. And don’t try the Olympics qualifying route. The USTAF certification for Boston shows it’s too “downhill” for running a race to get to US Olympics qualifying.
One of the topics I plan to explore in the near future is just what impact these downhill marathons have, including: a) what portion of potential qualifiers come out of them and b) how much they actually improve a runner’s time.
Until then, my gut tells me that they contribute to the increase in qualifiers – but they’re a small piece of the picture and simply eliminating them wouldn’t set the clock back to 2019.
As for Boston, though, the current course does meet the current requirements from USATF to count as an Olympic qualifying time (for 2024).
I looked back at the course measurements, and USATF had three possible courses on record from 2014 – one with the traditional finish on Boylston, and two others with alternate finishes.
The alternate finishes had a net drop of 3.34m/km, which would exceed the 3.30m/km limit set by USATF-NJ for a 2024 OTQ. But the actual course used after 2014 had a net drop of 3.23.
The new course certification (measured in 2021) shows a slightly different net drop of 3.27m/km, although the start/finish are exactly the same. But regardless, that’s still below the 3.30m/km set by USATF-NJ. But this explains the change in the OTQ requirement from 3.25m/km (2020) to 3.30m/km (2024).
That’s not to say that 3.30m/km is an appropriate place to draw the line – or that a line should be drawn. But it’s worth pointing out that there’s a wide gamut of net drops – with some downhill races (i.e. Jack and Jill, Ventura, Colorado, Steamtown) being closer to Boston … and most of the REVEL races being in a league of their own at 30-40m/km.
Basically, any race where they drive you up the mountain, and then you roll down. There are a few of those.
My estimate is based off of one factor… the Chicago marathon. Because they adjusted there guaranteed entry times for 2025 as drastically as they did (between 10-40 minutes depending on the age group) and they adjusted the AD corral requirements by 10 minutes, this tells me that Boston is in for a shocking cushion that it likely hasn’t seen before. My estimate is ten minutes or more. Reality is, the field size of runners has massively increased, and the ability of these runners have increased as well.
Nice work on all of this!
Don’t know how large of an effect this would have – but my assumption is not all qualifying races are equal in likelihood to result in Boston registration. The race itself is roughly 20-25% Massachusetts residents, which highlights a strong bias towards local participation, and might suggest a larger impact on number of registrations than an increased number of qualifiers elsewhere. Or put another way, a hot Boston probably has a bigger effect on cutoff time than a hot Chicago.
Have you looked at this at all?
My intuition is that this effect will probably be subordinate to other hard-to-quantify factors (i.e., more new runners wanting to run Boston, post-covid travel trends, large numbers of people who missed the cutoff last year, etc), but it still feels like hot Boston has the potential to have a substantial moderating effect on final cutoff time.
Regardless, feels like uniquely hard time to model this!
If you’re a Medium subscriber, you could check out this article by Joe Drake: https://medium.com/@joesgottarun/a-deeper-dive-into-the-cutoff-time-for-the-2025-boston-marathon-7e1fd6da2818
He did some work on the question of how likely a qualified person is to apply, based on the race they qualified at. The highest are some downhill marathons (which people likely pick specifically to qualify). Boston ranks very highly, but Chicago is not far behind. London and Berlin are large races that provide a ton of qualifiers and a good number of applicants, but the percentage of their qualifiers that apply is much lower than Boston / Chicago.
I haven’t had a chance to really dive into that question, but I plan to look at it soon. I’ll probably do some preliminary analysis now and then look at it again next spring – once we can see who actually runs in 2025 and match them against their previous results.
Seems like the 4% shoes have lowered the time hmmmm about 4% if you ask me.