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Discussion Forum - Hundreds - Start Times and Checkpoint Opening Times

Author: Mike Childs
Posted: Tue 17th Apr 2018, 18:57
Joined: 1990
Local Group: Dorset
Keir, if it is a full moon, should we look out for werewalkers ? What do they want at midnight checkpoints ? On second thoughts best not ask....

Author: Keir Williams
Posted: Sun 15th Apr 2018, 18:27
Joined: 2017
Local Group: Kent
You prompted me to check Mike. Indeed it is a full moon on 29 May. Let us hope te sky is clear as well.

Author: Peter Jull
Posted: Sat 14th Apr 2018, 12:03
Joined: 2011
Local Group: Kent
The back of the field will catch the Port of Dover at dusk when it is most impressively photogenic, then the lights of Calais twinkling across the Channel and then of Ramsgate across Sandwich Bay. Embrace the darkness and enjoy the bigger cheer later finishers always get. There's plenty of space on the later coach if anyone wants to switch.

Author: Mike Childs
Posted: Fri 13th Apr 2018, 9:31
Joined: 1990
Local Group: Dorset
To join the "second night elite", you need to reach the 80 mile CP (approx) by 2200 on Sunday. i.e. nightfall.

To do this needs an average (including CP and breakfast stops) of 2.222 MPH for the first 36 hours. which is OK.

For the remaining 20 miles, you need to average 1.666 MPH which even with the "threat of darkness" is not THAT difficult really. Note that it is never completely dark and with a full moon, streetlights or reflected light pollution ther is always a bit of background +light. And the dawn is wonderful (even if it is raining).

There will be plenty of time for cups of tea and refreshments at the last few checkpoints, and perhaps a short lie down resting with your feet up at a comfortable, friendly and uncrowded CP. I have found the best way to approach the second night is to see it as a separate and unusual short event with its own challenges. And pleasures - I will never forget hearing the nightingales singing on the second night of the Downsman

Author: Mike Childs
Posted: Thu 12th Apr 2018, 21:42
Joined: 1990
Local Group: Dorset
The "sunday night and monday morning team" on a 100 are a honourable and select elite. The "qualifying" preliminary event is to get that far...

Author: David Wainwright
Posted: Mon 9th Apr 2018, 19:02
Joined: 2013
Local Group: Cornwall & Devon
Thanks Deirdre, I am sure the support and friendship on the second night is top drawer. My only experience of it bears that out. It was on the truly memorable S Wales 100. There were loads of companions on that long, long, night. Pity was that actually only one of them was real.....!

Thanks for all the replies, but I will take the absence of a reply from the organisers to mean no timing reviews are likely, which is absolutely fine and absolutely their prerogative. My start time will stay at 1000...greatly looking forward to the date!

Author: Deirdre Flegg
Posted: Sun 8th Apr 2018, 20:21
Joined: 1993
Local Group: Dorset
'Threat' of darkness??!! Don't worry: oddly, it is not as bad as the first night & the company is better.

Author: David Wainwright
Posted: Sun 8th Apr 2018, 18:04
Joined: 2013
Local Group: Cornwall & Devon
Hi Chris, absolutely right, its not just the first one, its the pace throughout! I think I will stick to the 1000 start though as I cant bring myself to start anything as late as 1400, with the exception of an afternoon nap that is! I recall we finished the North Yorkie 100 together, all the best for this one if you are "in"!!

Author: Chris Pitt
Posted: Fri 6th Apr 2018, 22:57
Joined: 2004
Local Group: Dorset
David, If you think you are going to bump against CP opening times it is important that you look at the pace you are then restricted to between the following CPs. This may influence your choice of start time.

Author: C Mark Edwards
Posted: Fri 6th Apr 2018, 11:17
Joined: 1980
Local Group: Merseystride
David - having started this discussion some 7 months ago, I would agree that there could still be some issues at the early checkpoints - but the organisers have improved things since the original timings. I think that the current early times are broadly consistent with a 35 hour finish - so you may just about be OK. I'm expecting to be near to the start times for some of these checkpoints, but will just have to relax my pace and enjoy the checkpoints in the early stages. Like you, I don't want to start later than 10:00 due to the threat of Sunday night darkness.

Author: David Wainwright
Posted: Thu 5th Apr 2018, 21:20
Joined: 2013
Local Group: Cornwall & Devon
Hi Peter, really looking forward to the event now. In trying to make sure I had picked the right start time and working my usual starting pace through (in 5 events I'm a 35 to 38hr sort of a chap), I am worried that I will still arrive at Checkpoints 2 to 6 before their opening times.

I am not sure if I am alone in this, but I really REALLY don't want to start as late in the day as 1400. That then guarantees a second night out which shouldn't really be necessary. I see all the discussions on pacers and algorithms (?!) and I'm not trying to be awkward, but is there going to be any review of some of these opening times as I maybe I'm not the only one having doubts about the start time they picked?

Author: Peter Jull
Posted: Thu 5th Oct 2017, 10:57
Joined: 2011
Local Group: Kent
It has been agreed that anyone expecting to complete the Cinque Ports Hundred in under 32 hours should select a 2pm start time when entries open on Monday.

The early checkpoint opening times will be recalculated to reflect this while avoiding queues so please abide by the above guidance rather than planning to get through a checkpoint on the minute of the opening time shown.

Author: David Morgan
Posted: Tue 3rd Oct 2017, 8:31
Joined: 1994
Local Group: South Wales
Hi Peter,

Firstly, it's a relief to know that this isn't causing sleepless nights!!

The calculator already takes all that you raise into account. You can work out the average speed required for an overall timed finish of say 28 or 32 hours.
The beauty of the calculator is that you can adjust each section individually to take into account local factors.

So, knowing that your entrants are likely to start at a fast pace, you can add this to the various sections. Looking at historical data you will know that the pace slows and so on later sections that pace can be adjusted. The height ascent and distance adds the required information.

As outlined in a previous update, Cinque Ports have had access for some time and recently they've been added to the Pacer page.

If not for Cinque Ports, then they will be useful on future challenge events for ALL groups to use.

DM

Author: Peter Jull
Posted: Tue 3rd Oct 2017, 2:22
Joined: 2011
Local Group: Kent
=StartRate-(AVERAGE(D18:D19)*0.01)-(E19/C19/450) is definitely an algorithm. The LDWA Standardisation of Events Checkpoint Opening Times Calculator v1 uses it to calculate a degree of deceleration according to the distance into the event the walker has travelled.

Other algorithms reduce speed by 15% during legs the leading walkers will be doing in the dark and according to the amount of ascent in each leg, which seem to give reasonable results.

But the deceleration due to distance algorithm doesn’t produce a deceleration curve steep enough to accord with Mark’s research. I believe Dorset used the calculator which may account for the queue reported at CP1. It produces a speed for leg 1 20% faster than the overall average at the finish rather than the 43% revealed by Mark.

Rather than having a starting speed input variable it would more user friendly for event organisers if that were replaced by a planned fastest finish time. With split start times, changing that variable would be quick way of determining when checkpoints need to start opening to account for later starters eg <32hour finishers @ 2pm rather than >32 hours starting @ 10am. At the moment changing the start speed changes the overall finish time rather than the gradient of the deceleration curve.

To achieve that desired result I found it easier to adjust the local factor variable which is intended to account for underfoot conditions such as a leg consisting mostly of Welsh mountain bogs (not that any organiser would include such a leg).

Perhaps Mark could be copied in to the existing calculator with a view to providing a revised version of the deceleration algorithm that works in line with his findings. This non statistics/maths geek got stuck on the reasoning for the 450 constant. On the Cinque Ports 100 with much of the ascent concentrated into a few legs and likely to be firm underfoot for much of the way the distance factor will have the greatest impact on opening times.

The timing of this post should not be taken as an indication the issue is causing sleepless nights!

Author: David Morgan
Posted: Mon 2nd Oct 2017, 20:11
Joined: 1994
Local Group: South Wales
Hi Neil,

The opening calculator takes the following into account.

1. Distance.
2. Height Ascent
3. Speed

The speed will be altered by the user, and for the start of an event would probably be set at 5.5mph as people always start quickly.
So, the user of the calculator can adjust it to identify what time someone is likely to arrive at a checkpoint.

If it was set for 3.5mph then clearly the checkpoint opening time will be later.

There are no algorithms.

It comes down to when you want your checkpoints to open taking into account terrain combined with the knowledge that people always start quickly.

The calculators are under AdminHundred (limited access to 100 organisers and shared with Cinque Ports) and PACER pages.

DM

Author: R Neil Higham
Posted: Mon 2nd Oct 2017, 17:46
Joined: 1980
Local Group: Kent
Hi, Mark

We - the CP100 Committee - would like to see your algorithm etc if at all possible. Please would you send to merchandise.cp100@ldwa.org.uk and this should then get to me. Many thanks indeed.

One point of interest (and maybe David M's sheet will show this, when we find it!) is whether you make any allowance for extra time at Brekkie, eg 30mins or 60 mins; studying your timings seems (to me) to suggest that no allowance is made (as the mph is only slightly less at the next Checkpoint, ie there is no step jump in mph, which I might have suspected), so the question then becomes 'Should we?' The point here is that if we do, then the pre-Brekkie Checkpoint opening timings should be even earlier (albeit only marginally) than a smooth deceleration would suggest.

Thanks

Author: David Morgan
Posted: Sun 1st Oct 2017, 19:22
Joined: 1994
Local Group: South Wales
Hi Ian - I'll send you the opening and closing calculators that have been made available for all walk organisers. They're on the PACER Admin pages, but I'll send separately.
D

Author: Ian Lauriston
Posted: Sun 1st Oct 2017, 14:14
Joined: 1995
Local Group: Northumbria
Mark

I have read through your posts with interest. We are currently engaged on the preparatory work for the 2019 Northumbria 100. If I were to provide you with a checkpoint schedule c/w distances and any other material that might be relevant would you perhaps be prepared to draft opening and closing times as per your calculations? You might choose to include any comments as to start times including how many in your opinion would be optimal. I can give you my e-mail address if you are interested in this as I'd prefer not to have these exchanges in public.

Author: C Mark Edwards
Posted: Sat 30th Sep 2017, 19:05
Joined: 1980
Local Group: Merseystride
Merrian - that is interesting - and I think it supports my point.

Interestingly at the Dorset 100 I arrived at CP1 just 5 minutes after the opening time, and I remember making sure I didn't hurry to get there. The opening time for this CP allowed a 4.2mph pace from the 10:00 start. Next year's proposed start times allow a 3.9mph pace to CP1 (and only 3.6mph to CP2). Thus it is likely that many more than 50 people would want to arrive earlier at CP1 next year with the proposed times.

If I look at the Dorset opening times, they are broadly conistent with my deceleration algorithm (rather than a constant speed), based on a 32 hour pace starting 10:00 or 22.5 hour starting 14:00. CP1 opened marginally later (10 minutes) at a time consistent with a 34 hour finish allowing for deceleration. I think about 40 of the 10:00 starters finished within 34 hours so that is pretty consistent with 50 people arriving early.

The present proposed times for next year are based on linear opening times with the 28/20 hour schedule for the two start times, and linear closing times for a 10:00 Monday finish. I believe that the benefit of a later start time is to significantly postpone the opening time of the latter CPs, rather than a much smaller effect on the earlier CPs. If we had a mass start at 10:00 and still wanted to allow for a 20 hour schedule, this would mean that all the later checkpoints would need to open 4 hours earlier, and the earlier checkpoints would also have to have an extended opening time, but not as much as 4 hours.

If we take the base point as the total duration of checkpoint opening times with the proposed open/close times (224 hours), and then look at the differences that various other strategies would make, I calculate:

1. 28 hour (10:00), 20 hour (14:00) with deceleration: +17 hours
2. 30 hour (10:00), 20 hour (14:00) with deceleration: +13 hours
3. Mass start 10:00, 20 hour schedule, linear pace: +44 hours
4. Mass start 10:00, 20 hour schedule, deceleration: +57 hours

I'd go for 2 above as the best option to minimise congestion at the earlier CPs (of benefit to helpers and walkers alike), minimise overall CP opening time (benefit to helpers) and ensure that no walker is forced to walk into the second night due to starting later than they would ideally like (benefit to walkers).

If anyone wants the spreadsheet that I've used to do these calculations, please let me know.

Author: Merrian Lancaster
Posted: Sat 23rd Sep 2017, 17:48
Joined: 1996
Local Group: Beds, Bucks and Northants
Mark, a couple of things....

Were you aware that, at checkpoint 1 on the Dorset 100, we had to hold 50 people who arrived before the checkpoint opening time?

Have you considered how a mass start would affect the checkpoint opening and closing times?

Author: Peter Jull
Posted: Thu 14th Sep 2017, 15:56
Joined: 2011
Local Group: Kent
Thank you from someone for whom finishing before the 2nd sunrise is never going to happen and therefore less sympathetic to, but understanding of, the motivations of the 32 hour bracket finishers. Having spent 24 hours at the Malton finish waiting for a 48 hours dead (on his feet) finisher you can't beat the emotion and atmosphere of getting back in the last couple of hours. The committee will undoubtedly debate.

Author: C Mark Edwards
Posted: Thu 14th Sep 2017, 12:26
Joined: 1980
Local Group: Merseystride
In response to Peter - here are the times for 28/30/32 scheduled using the deceleration algorithm. Here I have left the later checkpoint times as calculated and have not overwitten with the earlier times from the 20 hour schedule starting at 14:00.

I wouldn't go as far as expecting a 32 hour walker to start at 14:00, as this gives an expected finish time of 22:00 on Sunday which is when it gets dark and so any delays would cause them to walk into the night. Thus they would be more likely to want to start at 10:00 leading to the possibility of queuing at the early checkpoints. So I wouldn't go for anything slower than a 30 hour schedule setting the opening times.

CP___ Miles___ 28 Hour___ 30 Hour___ 32 Hour
00___ 000.0___ Sat:10:00___Sat:10:00___Sat:10:00
01___ 006.5___ Sat:11:10___Sat:11:20___Sat:11:20
02___ 012.1___ Sat:12:20___Sat:12:30___Sat:12:40
03___ 018.4___ Sat:13:40___Sat:14:00___Sat:14:20
04___ 024.3___ Sat:15:00___Sat:15:30___Sat:15:50
05___ 031.5___ Sat:16:50___Sat:17:20___Sat:17:50
06___ 041.1___ Sat:19:20___Sat:20:00___Sat:20:40
07___ 044.4___ Sat:20:20___Sat:21:00___Sat:21:50
08___ 048.9___ Sat:21:40___Sat:22:30___Sat:23:20
09___ 057.8___ Sun:00:10___Sun:01:20___Sun:02:20
10___ 066.6___ Sun:03:00___Sun:04:10___Sun:05:20
11___ 072.5___ Sun:04:50___Sun:06:10___Sun:07:40
12___ 077.7___ Sun:06:30___Sun:08:00___Sun:09:30
13___ 083.2___ Sun:08:10___Sun:09:50___Sun:11:30
14___ 089.3___ Sun:10:10___Sun:11:50___Sun:13:40
15___ 093.9___ Sun:11:40___Sun:13:30___Sun:15:20
16___ 097.5___ Sun:12:50___Sun:14:40___Sun:16:40
17___ 101.0___ Sun:14:00___Sun:16:00___Sun:18:00

Author: Peter Jull
Posted: Wed 13th Sep 2017, 16:34
Joined: 2011
Local Group: Kent
It would be helpful to see your table Mark, recalculated on the basis that 32 hour and under finishers (rather than 28) start at 2pm. Using your deceleration data it would be straightforward enough but I expect you have algorithms set up to do it more readily.

Author: Michael Headley
Posted: Mon 11th Sep 2017, 14:13
Joined: 2008
Local Group: Kent
Thanks to Mark for his thorough review of the current proposals for checkpoint times on the Cinque Ports 100. It will take time to work through his detailed suggestions so this is by way of an acknowledgement of the points he raises. More later no doubt - and, for a week or two, there's an opportunity for further contributions...

Author: Deirdre Flegg
Posted: Fri 8th Sep 2017, 18:58
Joined: 1993
Local Group: Dorset
Mark-you have made my day, after a Dorset drenching! I won't attempt to answer ( some may be relieved to hear) & will leave to the other mathematical buffs

Author: C Mark Edwards
Posted: Thu 7th Sep 2017, 19:02
Joined: 1980
Local Group: Merseystride
It wouldn’t be a 100 without some sort of discussion on start times and checkpoint opening times, so I thought I’d start one off! Given the start times of 10:00 and 14:00 for the Cinque Ports 100, and the checkpoint opening times on the website, I can foresee that there will be problems with queues at the early checkpoints with many people arriving early – this is likely to cause problems of congestion for both the walkers and the checkpoint volunteers. It may be that the website opening times are only provisional and will change, in which case these problems may not arise. In any case, I think the analysis I have done to arrive at this conclusion is interesting (at least to data buffs like me!) – and it may prompt a re-think of the timings. I will go into some detail about how I have come to this conclusion – so well done if you read through all of this post.

I have completed 25 LDWA 100s (+ 1 unofficial 100) – the first four of these had times of 44 hours or more and thus meant walking through both nights. For the following 22 hundreds I have finished in time to get to bed on Sunday night, and I now have a fairly consistent finishing time of between 33 and 36 hours. This means that if I start at 10:00 I can be pretty confident of finishing before it gets dark on Sunday (~10pm), but that if I were to start at 14:00 then I would be almost guaranteed to have to walk into the second night. When I talk to other walkers near the start of a 100 (after we have sorted ourselves out in the first few miles), the overwhelming aspiration on finish times is to finish in the light on Sunday – this gives a great psychological gain, and I think that this should be taken into account when planning opening times.

On this basis, it would be reasonable that a walker/runner should be OK with starting at 14:00 if they are still confident of finishing in the light on Sunday – this gives 32 hours, and allowing a lee-way of 2 hours for being slower than expected, this would mean that anyone expecting to finish in 30 hours or less should be happy to delay their start to 14:00, and those expecting to take >30 hours should start at 10:00.

The Cinque Ports checkpoint opening times appear to be based on a 28 hour finish time at a constant speed of ~3.61mph starting at 10:00 (sets time for CPs 1-8) and a 20 hour time at a speed of ~5.05mph starting at 14:00 (sets times for CPs 9-finish). At first glance this may seem fine as a cut-off of 28 hours is quite reasonable and more generous than the 30 hours I’ve suggested above. But of course we all know that it doesn’t really work like that, as (unlike elite athletes) we will slow down as we get further through the walk. The reasons why we slow down are many, but include:

• We spend longer at checkpoints later in the event – we arrive at CP1 with no time spent stopped and are likely to have only brief breaks to start with, and longer breaks later in the event (particularly the breakfast CP). As an example, looking at my own timings over the past 20 hundreds, I spend an average of 2 hours stopped at CPs in the first 50 miles, and 4.5 hours in the second 50 miles.
• We slow down for many physical reasons such as blisters, aches, tiredness, sickness, low energy, you name it ….
• We slow down when it gets dark
• We slow down for mental reasons when it gets harder to make decisions and be confident of route finding

So it is reasonable to ask the questions as to what times a walker might be expected to get to each CP for a given finish time. Fortunately we now have a lot of data to answer this question as the recent results have the CP arrival times for each walker. I have looked at the times for all the finishers of the last 2 hundreds (Dorset at NYM) and have determined the following, based on some 687 hundred completions:

• The average speed in the first section from the start to CP1 is ~143% of the overall average speed – so someone who completes a hundred in 30 hours, with an overall average speed of 3.4mph, can be expected to reach CP1 at a speed of 4.9mph. Or looking at this the other way round, someone who arrives at CP1 at a speed of 3.6mph can expect an overall average speed of 2.5mph and a finish time of almost 40 hours (involving 4 hours of second night darkness).
• Some 90% of walkers reach CP1 at a speed faster than 128% of their eventual overall average speed – so we all display a similar pattern of slowing.
• Well over half the hundred finishers take less than 40 hours so, with the present opening times, more than half of the walkers will have to start at 14:00 to avoid arriving early at CP1! The alternative (and more likely scenario) is that there will be a queue of at least 150 people waiting for the checkpoint to open.
• By the time a walker reaches 25 miles, the average speed will be down to 130% of the overall average, at 50 miles it is 115%, and at 75 miles 105%. The figures that we can be confident that 90% of walkers will exceed are 121%, 110% and 102% at these distances.

Given this ‘normal’ profile for slowing, it is possible to calculate what opening times are consistent with a particular overall average speed and starting time. Using the 28 hours (10:00) and 20 hours (14:00) targets, this gives opening times (present and suggested revision) as follows (apologies can't get the table to format nicely):

CP____Miles___Present______Revised_
Start__0_______Sat:10:00____Sat:10:00
1_____6.5_____Sat:11:40____Sat:11:10
2_____12.1____Sat:13:20____Sat:12:20
3_____18.4____Sat:15:00____Sat:13:40
4_____24.3____Sat:16:40____Sat:15:00
5_____31.5____Sat:18:40____Sat:16:50
6_____41.1____Sat:21:20____Sat:19:20
7_____44.4____Sat:22:10____Sat:20:20
8_____48.9____Sat:23:30____Sat:21:40
9_____57.8____Sun:01:20____Sun:00:10
10____66.6____Sun:03:10____Sun:02:10
11____72.5____Sun:04:20____Sun:03:30
12____77.7____Sun:05:10____Sun:04:40
13____83.2____Sun:06:20____Sun:05:50
14____89.3____Sun:07:40____Sun:07:10
15____93.9____Sun:08:30____Sun:08:20
16____97.5____Sun:09:10____Sun:09:10
End__101_____Sun:10:00____Sun:10:00

So – in summary – can I request that the CP opening times are reconsidered (if indeed the present suggestions are not just provisional) in order to avoid much over-crowding and congestion at the early checkpoints?

Thanks for reading this far.