Running a Boston Qualifying Time in Berlin

An analysis of BQ times and pacing strategies in the Berlin marathon.

Introduction

In this post we use results from the last 8 years of the Berlin Marathon — 276,008 runners, including 208,850 males and 67,157 females — to explore how often participants achieve their Boston Marathon qualification standard (BQ), answering the following questions as we go:

  1. How often do male and female runners from different age groups achieve their BQ time?
  2. When they achieve their time, how much margin do they typically enjoy?
  3. When runners fail to achieve their time, how much do they miss by?
  4. How do the pacing patterns of those who achieve their BQ times differ from those who miss theirs?

In the end we will provide specific advice, for male and female runners, across the different age groups, as to the pacing targets they should aim for in order to achieve their BQ time. This advice will be based on the typical pacing patterns of male and female runner who sucessfully achieve their BQ times in a given age-group.

The Boston Marathon Qualification Standard

With the 2018 Berlin Marathon just around the corner many participants will be giving careful consideration to their desired goal-time and pacing as they plan to get the most from Berlin’s fast course. Ten world records have been achieved on the Berlin course over the years and the excitement is building about whether favorites Eliud Kipchoge(Kenya) and Tirunesh Dibaba (Ethiopia) might be planning something extraordinary on the day.

Most participants will have their own records in mind as many hope to achieve new personal-bests, perhaps even securing their qualification time for the fabled Boston Marathon. The Boston Qualification (BQ) time is one of the marathon’s best known, and most sought after, ‘good for age’ standards. It is based on the age and gender of runners. The table below shows the qualification standards for the 2019 Boston Marathon, which must be achieved by runners on or after Saturday, September 16, 2017; these qualifying times are based upon each athlete’s age on the date of the 2019 Boston Marathon (April 15, 2019). Unfortunately, achieving one’s qualifying time does not guarantee entry into the event, but simply the opportunity to submit for registration. In recent years, not all qualifiers who submit an entry have been accepted due to field size restrictions, and in such circumstances those who are the fastest among the pool of applicants in their age and gender group have been accepted.

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

BQ Rates and Margins in Berlin

We define the BQ rate to be the proportion of runners in a given age group who achieve the BQ time for that age group. In Figure 1(a) below we see the BQ rates for male and female runners, based on their age groupings. For example, the BQ rate for runners in the 18–34 age-group is just over 0.1, indicating that just over 10% of runners in this age group manage to achieve their qualficiation times (3 hours and 5 mins for men or 3 hours and 35 mins for women).

Interestingly we see how BQ rates tend to rise significantly with age. For example, runners in their 40s look to be achieving their qualification standards almost 15% of the time. Is this because of the benefit of experience, as older runners tend to be more experienced runners?

Moreover, while the BQ rates for men and women are very similar for younger participants, they differ as runners age beyond their 40s, when women seem to enjoy a distinct advantage. For example, a male Berlin participant in his 60s is associated with a BQ rate of about 20%, but for a similarly aged female runner it is closer to 30%. Does this suggest that older female runners are really out-performing their male counterparts?

Figure 1. BQ rates and margins for the Berlin Marathon (2010–2017)

Focusing on whether a runner achieves their BQ time is a rather binary outcome. Two runners might achieve their BQ time but one might do so with minutes to spare while another might just make it. Likewise, when a runner fails to achieve their BQ time, how much they miss by can be informative. We call this their BQ margin, which is simply the relative number of minutes by which they come in above or below their BQ time. For example, the qualification standard for a 50–54 year-old women is 4 hours (240 minutes). If such a participant achieves a time of 216 minutes then they will have come in 24 minutes below their BQ time and their BQ margin will be 0.1 (24/240); they have achieved their BQ time with a margin of 10%. If instead their finish time was 252 minutes then they will have missed their qualficiation time by 5 minutes and their BQ margin will be 0.05 or 5%.

Figures 1(b) and (c) show the BQ margins for runners who (b) achieve and (c) miss their BQ times. In Figure 1(b) we can see that when runners achieve their BQ times, whether male or female, they tend to do so with a margin of just under 0.1, decreasing slightly with age. In other words, although a greater proportion of older runners tend to achieve their BQ times they do so with slightly less of a margin.

In Figure 1(c) we see the corresponding margin for those runners who fail to secure their BQ times, and once again the margin tends to decrease with age, albeit much more dramatically than was the case with successful BQ runners. In other words, older runners tend to miss their BQ standard by an ever-decreasing margin, getting closer and closer to their qualification times. Unsuccessful younger males (18–34 age group) tend to miss their 3 hour and 5 minutes standard by a little over 30% (approximately 1 hour) whereas 60–64 year-old men tend to miss their 3 hour and 55 minute standard by just over 20% (about 50 minutes). It’s a similar story for women except that across all age groups, women enjoy less of a margin (they get closer) than men when their miss their BQ standard.

One way to interpret this is that runners who succesfully achieve their BQ times do so in a similar manner, whether male or female, but when runners fail to achieve their BQ times, then men tend to miss by a much larger margin than women. One explanation for this is the well documented higher rate of hitting the wall among men, compared to women; runners who hit the wall rarely, if ever, achieve their BQ times and because many more men hit the wall than women we can expect their times to suffer more. However, it is worth noting, although not shown here, that even when we account for this (by removing all runners who hit the wall) women still continue to enjoy superior BQ margins to men when they fail to meet their BQ standards.

Negative/Positive Splits and BQ Rates

How should one run in order to achieve a BQ time? Fast! Ok, let’s try that again. Am I more likely to achieve a BQ time by running a positive split (faster first half than second) or a negative split (faster second half than first), or does it matter?

To answer this question we split our Berlin runners, based on their halfway times, into those that run a positive split and those that run a negative split. In Figure 2(a) we can see how negative splits are much less common than positive splits, across all age groups. For example, about 15–20% of younger runners run negative splits, but for runners in their 50’s the negative split rate has falls to about 10%. Interestingly, the negative split rate is consistently higher for women than for men, across all of the age groups, although this modest difference is itself decreasing with age.

Figure 2. The effect of positive and negative splits in BQ success.

In Figure 2(b) we compare the BQ rates for men and women based on whether they run a positive or a negative split. It is clear that there is an advantage to running a negative split, regardless of gender or age. For example, only 10% of younger runners (18–34 years old) who run a positive split achieve their BQ time. By comparison, for the same age group, almost 20% of those who run a negative split achieve their BQ time. In other words, among 18–34 year olds, those running a negative split are up to twice as likely to achieve their BQ time compared to those running a positive split. This negative split benefit persists across all of the age groups too; and once again it survives even if we remove all runner who hit the wall (extreme positive splits) from consideration.

In Figure 2(c) we quantify this negative split benefit more precisely by calculating the ratio of BQ rates between negative and positive splits. So a negative split benefit of 2 means than twice as many negative splitters achieve their BQ standard than positive splitters. We can see in Figure 2(c) how women enjoy a consistently higher negative split benefit across all age groups, compared to their male counterparts. In other words, not only are negative splits more common among women they are even more likely to be associated with a successful BQ time compared to men.

Pacing Strategy and BQ Rates

So, negative splits seem to help when it comes to achieving a BQ time — while, acknowledging that correlation is not causation — but what about a more detailed pacing strategy? In our Berlin dataset we have access to the timings of runners at 5km intervals. This means we can calculate their pacing across each of the 5km segments from the start to the 40km mark, and from the 40km mark to the finish-line (2.195km). Moreover, for each runner we can turn their actual segment paces (e.g. 5 mins/km) into relative paces by dividing their actual pace for a segment by their average pace over the entire race. For example, if a runner runs the first 5 km at 4 mins/km and their average pace is 5 mins/km then their relative pace for the first 5km is 0.8, indicating that they ran it 20% faster than their average pace. Then we use the relative segment paces for runners as their pacing profile, to signal whether they ran a particular part of the race faster or slower than their average pace.

Figure 3. Pacing profiles for runners who succeed or fail to achieve their BQ times.

Figure 3 shows the pacing profiles of runners for Berlin — (a) all runners, (b) males, (c) females — separating those who achieve their BQ times (BQ Success) from those who do not (BQ Failure); while accepting that there is no such thing as a ‘failure’ in the marathon! Each individual line corrsponds to a different age group with the solid lines corresponding to the 18–34 year olds and the dashed lines to 65–70 year old runners; the paler, thinner lines correspond to each intermediate age group.

The main message to draw from these graphs is that that the pacing profiles of those who achieve their BQ times are less varied than those who do not. For example, in Figure 3(a), among all runners, those who achieve their BQ times tend to start the race less than 5% faster than their average pace (relative pace < 0.95) and they tend to finish about 5% slower (relative pace ~ 1.05). By comparison, those runners who do not make their BQ times tend to start up to 10% faster and finish about 7–10% slower. It’s a similar pattern for men and women, as shown in Figures 3(a & b).

It is also the case that as Berlin runners age, the pacing profiles become more varied. Older runners, even those who achieve their BQ times, tend to start a little faster and finish a little slower than younger runners. The effect is slightly more exagerated for those who miss their BQ times and once again we see the same effect for men and women.

How Should I Pace my BQ Attempt in Berlin?

How might this help us to pace our own BQ attempts in Berlin? Is there a set of recommended paces to run a successful BQ that is tailored to Berlin? In fact this is quite straight forward to determine, by calculating the average segment pacing of those who have achieved their BQ times in Berlin. By doing this we can produce a set of paces that in some sense reflects the reality of the Berlin course, as opposed to using a simple one-size-fits all pacing model. And so, in the tables that follow we present these paces for men and women across the different age groups, for positive and negative splits.

To use these pacing tables simply find the table and row that corersponds your gender, preferred split type (psitive or negative) and age group, and note the 1-km paces for each of the segments of the race. For example, for a 45–50 year old male, aiming to to make their BQ time using a positive split, we use the 45–50 row in Table 1. This recommends starting their race by running the first 5 kms at 4m 41s per km, then speed up marginally over the next 15 km (4:40min/km for the 5–10 km segment, 4:39min/km for the 10–15 km segment, and 4:41min/km for the 15–20 km segment), before slowing over the remainder of the race (4:46, 4:52, 4:59, 5:14, 5:09min/km) to finish in approximately 204 mins; the target qualficiation time is 205 minutes. For the same runner, if they wish to instead run a negative split then the recommended paces are in the corresponding row Table 2 and for female runners its Tables 3 and 4.

Male BQ Pacing

Positive Splits

Table 1. Male BQ pacing for positive splits.

Negative Splits

Table 2. Male BQ pacing for negative splits.

Female BQ Pacing

Posiitve Splits

Table 3. Female BQ pacing for positive splits.

Negative Splits

Table 4. Female BQ pacing for negative splits.

One minor point worth making, for the sake of accuracy, is that in computing these average paces we have focused on those runners who achieved their BQ times with no more than a 1% margin. This ensures that the paces provided match a BQ time that is just under the qualification standard. Had we included all of the BQ qualfiiers then we would have produced pacing tables with more ambitious times, which is probably less useful, and certainly more risky, for most runners. In any event, if a runner wishes to target a more ambitious BQ time then they can always borrow the pacing from a younger age group.

Conclusions

Running a BQ time is far from straightforward and most don’t manage it. Those who do, achieve it by pacing themselves carefully — not starting too fast to avoid finishing too slow — and there is some evidence that a negative split may increase the likelihood of securing a BQ time.

The BQ pacing tables above provide concrete pacing recommendations to achieve a BQ time in Berlin. They have the advantage that they are based on the real experience of Berlin runners who have achieved their BQ times in the past. If they help you please let me know!