Monday, August 24, 2015

Santa Rosa Marathon sways Boston Cutoff

UPDATED! The analysis has been updated. The latest analysis is available here: http://boston-qualifier-stats.blogspot.ca/2015/09/final-projected-boston-marathon-2016.html


With 24 of the top 25 feeder marathons complete, the current trend for the 2016 Boston Marathon Cutoff is 93 seconds (92 if you're an optimist). The Santa Rosa Marathon had 205 more finishers this year than last, and an additional 96 people who met the 1m2s cutoff from last year. With a field of 1400 runners this year, this medium sized marathon surprisingly was able to influence the BQ cutoff trend quite significantly (+3 seconds).

Only 1 more left, the infamous Mike Rossi Marathon... Lehigh.

The Caveats:
The analysis assumes a lot of assumptions. I have outlined the objective and methodology on this page. Basically, I look at the number of people who qualified for the 2015 race, using the "feeder marathons". To qualify for the 2015 race, participants needed a BQ minus 1m2s. These races were all run last year. I then look at the same races for this year, and see how many people would qualify using the same cutoff.  If fewer people qualify, then I decrease the cutoff (make it easier to qualify), until the same number of people qualify as did last year. Conversely, if more people make the 1m2s cutoff than last year, I increase the cutoff (making it harder to qualify) until the same number of people qualify.


Table 1: Year vs Year, By Marathon
2015 Qualifying Year2016 Qualifying Year
MarathonFinishersBQBQ2015BQ2015%FinishersBQBQ2015BQ2015%
Big Cottonwood1,30826224419 %1,52728425217 %
Erie 97831228029 %95931728930 %
Berlin 36,1225,7695,45515 %29,0274,5304,30815 %
St. George 5,8181,1981,13720 %5,80699793916 %
Twin Cities 8,8551,01095311 %8,8531,04196711 %
Portland 6,9455044707 %6,4294293956 %
Chicago 38,8543,5273,3149 %40,5814,0043,7629 %
Steamtown 2,16537735917 %2,18443140819 %
Columbus 5,52361156110 %5,44562058111 %
Toronto Waterfront 3,60448745313 %3,97165460115 %
Baystate 1,30430127121 %1,53137835023 %
Marine Corps 23,3851,1701,0735 %19,6877186623 %
New York City 50,1343,9803,7257 %50,4333,6293,4007 %
Indianapolis Mon'tal 3,52151848314 %3,72559455215 %
Richmond 4,8424414189 %5,09552048710 %
Philadelphia 10,9141,3411,25211 %10,3331,3371,23512 %
California International 6,2381,2921,19519 %5,7931,2911,18520 %
Houston 6,9456986519 %7,1336986489 %
Boston 31,21010,56410,04632 %26,63512,79212,21846 %
Bayshore2,01731430015 %2,00834132916 %
Ottawa5,32481274514 %4,50180675017 %
Mountains 2 Beach1,61739937023 %1,58645241926 %
Grandma's 6,1731,1081,04717 %6,0751,1341,06618 %
Santa Rosa1,23125822218 %1,43634131822 %
TOTAL265,02737,25335,02413 %250,75338,33836,12114 %
Notes:
1. BQ = Number of Runners who met the minimum Boston Qualifying Standard
2. BQ2015 = Number of Runners who met the Cutoff for the 2015 Boston Marathon (BQ minus 1m 2s)
3. BQ2015% = Percentage of finishers meeting the BQ 20015 cutoff time.
4. AG = Age Group on the day of the feeder race, not the subsequent year's Boston Marathon.
   This is a small source of error, as a person may "age-up" for the subsequent year's Boston Marathon.

Analysis
Looking at the table above: 265,027 runners finished a 2015 "feeder" qualifying race, whereas 250,753 finished a 2016 "feeder" race: 14,274 fewer people. However, more people met the minimum BQ standard 38,338 for the 2016 qualifying year versus 37,253 for the 2015 qualifying year. Moreover, 1097 more people met the 1 minute and 2 second cutoff in the 2016 qualifying year so far than did in 2015.

If the Boston Marathon registration opened today - assuming the same proportion of qualified runners apply for the race (see objective and methodology) - there wouldn't be enough spots for everyone. We have to increase the cutoff so that we whittle the 36,121 people (who met the 2015 cutoff in a 2016 qualifying race) down to 35,024 the number of people who met the Cutoff for 2015.

Through a numerical modelling approach, the answer to the solution, of what the cutoff should be becomes 93 seconds.

At 93 seconds, 35,017 people will make it into the marathon. (only 7 fewer than this year). For the optimists, at 92 seconds: 35,039 people will make it (15 more than last year).

Table 2: Projected qualifiers, from this years races, by AG based on an 93 second cutoff.
AGFinishersBQBQ minus 62sBQ minus 93sBQ2016%
F18-3442,7705,4125,0954,94612 %
F35-3917,2272,5402,4012,33214 %
F40-4416,6282,5622,3832,30414 %
F45-4912,4112,6102,4482,36619 %
F50-548,2101,6361,5491,50418 %
F55-594,11088383281820 %
F60-641,68039938237823 %
F65-6953611411211021 %
F70-7415832303019 %
F75-793055517 %
F80+633350 %
M18-3441,3975,1994,9454,80012 %
M35-3922,4732,7422,5652,49111 %
M40-4425,1173,2903,0832,97512 %
M45-4921,8603,9843,7463,62417 %
M50-5417,2503,0572,8552,75416 %
M55-5910,2291,9531,8481,78717 %
M60-645,3731,1581,1091,07420 %
M65-692,24654151951123 %
M70-7478517316716321 %
M75-7921235343215 %
M80+4510101022 %
Total250,75338,33836,12135,01714 %
Notes:
1. BQ = Number of Runners who met the minimum Boston Qualifying Standard
2. BQ minus 62s = Number of Runners from this year's races who would have met the Cutoff for the 2015 Boston Marathon (BQ minus 1m 2s)
3. BQ minus 93s = Number of Runners from this year's races who would meet the projected Cutoff for the 2016 Boston Marathon (BQ minus 94s)
4. BQ2016% = Percentage of finishers meeting the projected BQ 20016 cutoff time.
4. AG = Age Group on the day of the feeder race, not the subsequent year's Boston Marathon.
   This is a small source of error, as a person may "age-up" for the subsequent year's Boston Marathon.

Santa Rosa Marathon Results Comparison 2014 vs 2015

AG2014 Event2015 Event
FinishersBQBQ 2015BQ%FinishersBQBQ 2015BQ%
F18-34209433121 %225575425 %
F35-3986212124 %94222123 %
F40-44769712 %81191723 %
F45-4980222228 %87252229 %
F50-5452131325 %62121219 %
F55-59268431 %359826 %
F60-64101110 %136646 %
F65-6930 %72229 %
F70-7410 %0 %
F75-790 %0 %
F80+0 %0 %
M18-34179322718 %212515024 %
M35-3998141314 %106161315 %
M40-44100221622 %125262221 %
M45-49103252424 %126312925 %
M50-5486202023 %116282724 %
M55-5969151222 %83212025 %
M60-643311933 %37101027 %
M65-69100 %194321 %
M70-7450 %51120 %
M75-7941125 %20 %
M80+111100 %111100 %
Total1,23125822221 %1,43634131824 %
Notes:
1. BQ = Number of Runners who met the minimum Boston Qualifying Standard
2. BQ2015 = Number of Runners who met the Cutoff for the 2015 Boston Marathon (BQ minus 1m 2s)
3. BQ% = Number of Runners who met the minimum Boston Marathon Standard.
   This is a small source of error, as a person may "age-up" for the subsequent year's Boston Marathon.

9 comments:

  1. Just curious how close you were last year to getting the cut off right, assuming you were analyzing it. I was hoping for a larger field this year being that I'm only 88sec under. Hopefully you're off by a bunch:) thanks either way and good luck to all!

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    Replies
    1. This is the first time (and probably only time). I hope I'm wrong too as I only have 67 seconds!

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    2. Please, continue doing it year after year ha! I have 96 sec under and I'm enjoying/suffering each post of you :P

      Big hug

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  2. Just curious, I see that you have Erie 2014 on the list, and that was a double BQ race counting for both 2015 and 2016 Boston. But Erie 2015 is the same weekend as Lehigh, so it will count for Boston 2016, yet you say there's only one major feeder left. Doesn't that make 2 major feeder races left? Why won't you factor Erie 2015 into the analysis? Or will you :-)?

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    Replies
    1. Yes, the Erie is a double-qualifier, and has been for a while now. For Boston 2014, people could have used their 2012 and 2013 times. For Boston 2015, I am only going to compare Erie 2014 results and Erie 2013 results. While that might seem like a source of error, keep in mind that Erie is a small marathon, and by only comparing it once, it keeps the analysis and methodology consistent.

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    2. Well, what's more important; being "methodology consistent" or being accurate?

      Look, some years other marathons were Top-25 feeder races and other years it was different races. BAA isn't interested in being "consistent", they are interested in being accurate. Big Cottonwood didn't use to be a feeder, now it is. If a race like Erie is a double-dip race, then you should count both the 2014 & 2015 race.
      Otherwise, now that we all see you're more interested in being consistent, there's no point in coming here. We were coming here because we thought you would be accurate, not because you would be "methodology consistent".

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    3. By being consistent, with how he uses the results from each race, he is trying to be accurate. Be kind, please, Mike. Heavens knows you will be back to check again, next year, if you're a squeaker. Good luck with your running! All the best :)

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  3. Any official word on field size?

    ReplyDelete