[rconti]

Context:

There's a limit on how many people can run the Boston Marathon.

To qualify to "run Boston", you have to run another marathon in a qualifying time[1], prior to applying. For example, the qualifying time for a male 40-44 is 3h05m. For a female of the same age, 3h35. Non-binary, 3h35.

You submit your application and qualifying race and time, and then some time _later_, based on the number applications received that are within the cutoff (and it's always more than they can accept), they adjust the cutoff time downwards even further. That additional cutoff delta is the what's being calculated on the slider here. So if your published cutoff is 3h05, and the slider predicts a 6min delta, you need to have run 2h59, not 3h05.

1. https://www.baa.org/races/boston-marathon/qualify

[abeppu]

Methodologically, why would you have one cutoff vs a different cutoff per group (as there are different qualifying times per group)?

I am not a marathoner, but I'd imagine that a 6 min decrease from the stated qualifying time cuts out a larger proportion of younger runners (i.e. decreasing the threshold from 2h55 to 2h49 for men 18-34 seems like a much sharper cut than decreasing 4h20 to 4h14 for women 60-64). I would have thought you'd want to pick the delta by looking at the distribution within each gender x age pool.

[steadyelk]

It could be intentional. For a lot of folks, running the Boston Marathon is a dream, so maybe the BAA wants to make that dream just slightly more attainable the older you get.

[poutrathor]

As always it's probably because maths still is too hard for most people and keeping the rule simple won over fairness.

[votepaunchy]

Ironman just switched to age-grading, which is just as simple and already used by many runner training plans and race calculators.

https://www.ironman.com/news/age-group-qualification-system

[adrianmonk]

They can also improve that balance by adjusting the qualifying times from year to year, and they do.

They could even make a projection of future cutoff times and take that into account when setting the baseline qualifying times. In other words, be a little more generous with the 18-34 group initially knowing that you'll like penalize them more with your one-size-fits-all cutoff. I'm not sure if they do that.

Also, the current qualifying times are all multiples of 5 minutes. If they really want to improve balance between groups, the low-hanging fruit is to make those more granular.

[rconti]

Yeah, doing it by flat time delta rather than percent delta seems fundamentally flawed, but of course it makes it easier for the average person to understand.

I also don't understand what the motives are behind how the age/gender buckets are calculated in the first place. I'm not sure if it's public or not.

Are they:

* Trying to calculate based on an nth percentile finishing time across each bucket?

* Trying to ensure roughly equal percentages of applicants from each bucket get accepted?

* Something else?

[k2enemy]

Making sure they can accept a lot of high disposable income 40+ runners that will buy a lot of merch. The time cutoffs start to get much easier after 40.

[Guillaume86]

Doesn't look true, I inputed the times in an age grading calculator and 39 cutoff time was easier than 44, even if it's not very accurate I doubt it's "much easier".

[scott_w]

It’s a common problem. Time trialling uses Age Adjusted Time for events which uses a flat time reduction based on age. One guy pointed out the absurdity that he’s still extremely fast in his 50s, so his AAT end up impossibly fast, winning him a lot of events as a result!

[fsckboy]

>To qualify to "run Boston", you have to run another marathon in a qualifying time

just to add this to the mix: there are faster and slower marathon courses, so you can improve your qualifying time by running in one of them. "downhill" seems to be a promising factor.

https://findmymarathon.com/fastestmarathoncourses-state.php?...

[altcognito]

there is now a time adjustment for downhill, and extreme downhills are no longer qualifying

https://runtothefinish.com/downhill-boston-qualifiers/

[loloquwowndueo]

Dunno man, running downhill is murder for knees, I usually had to slow down instead of speeding up on down slopes.

[scott_w]

You’re not running down Helvellyn, it’s more the cumulative downhill that qualifies a “downhill” marathon. Remember this is 1500 feet drop over the course of 26 miles, so you’ll get the benefit of gravity without the downsides of steep drops.

[RandallBrown]

I ran a downhill marathon that was on a rail trail through the mountains. It was a very very gradual downhill the whole way.

My friend that ran it was mad at me when we finished because he thought parts of it were uphill (even though it wasn't.)

That race won't be a Boston qualifier next year.

[mmargenot]

You can also run for a charity by raising sufficient money for a cause that sponsors you.