Walmsley runs a fake 1:02 half, trail trolls loose their minds

Properly measured, Certified courses have a short course prevention factor added of 0.1% which equates out to 5 m for a 5k, 10 meters for a 10k, 21 meters for a half marathon and 42 meters for a half marathon. This is to ensure that if a record is set, the course is not found to be short upon a verification re-measurement.

Half marathon distance without the short course prevention factor=21097.5 m or 13.109378 miles. With the short course prevention factor=21097.5m + 21 m=21118.5m or 13.122427 miles.

In addition the extra distance of the short course prevention factor is added during part of the measurement protocol after the Jones Counter is calibrated. The extra distance (1.6 m/mile) is added to the calibration constant so that all of the splits are proportionally adjusted.

Running imperfect tangents is negligible. People recorded 13.2+ due to GPS error, which is worse in the sections with tall buildings in Houston.

WinnytheBish wrote:

I take back what I said about the GPS watch, even though they usually aren't completely accurate it seems as though there's reports of the course being short because of a misplaced cone.

More likely is the the GPS watch failed to pickup the exact point of the turnaround.

Moral: Never use a GPS watch for accurate measurement.

Shunpo wrote:

It’s good, it’s great! But it’s not top 10 lol I just love the strava comments, those people have no idea.

He will be top 10 when it counts and you'll go home devastated. Those 61-62 American half runners usually die badly in the full marathon.

Check my math. Marathon is 42195 meters by definition. Divide that by 2. Multiply by 1.001 to add short course protection factor. Divide by 1609.344, the exact conversion factor to convert to miles. 13.122 miles

GPS watch tracks will vary due to not running tangents as well as their own errors. But on a course like this with not many turns, a runner can come pretty close to the measured out distance.

zzzz wrote:

But on a course like this with not many turns, a runner can come pretty close to the measured out distance.

Yep, I just dug up previous years' Strava activities and the measurements were right around 13.1.

So I think 63-low is a fair estimate, which also matches the claim that the cone shortened the course by 274m

Yeah that’s what they’re suppose to do on paper but it’s always longer, there are plenty of certified halves that don’t run through cities with any buildings and people always get 13.2 or so. It’s really besides the point though, 1:03 low 1:03 mid, either way the point remains the same.

GeePeeEss wrote:

WinnytheBish wrote:

I take back what I said about the GPS watch, even though they usually aren't completely accurate it seems as though there's reports of the course being short because of a misplaced cone.

More likely is the the GPS watch failed to pickup the exact point of the turnaround.

Moral: Never use a GPS watch for accurate measurement.

It always advisable, when making a 180 turn on a course, to pause for a few potatoes to ensure GPS tracking catches you at farthest point.

wait for it wrote:

GeePeeEss wrote:

More likely is the the GPS watch failed to pickup the exact point of the turnaround.

Moral: Never use a GPS watch for accurate measurement.

It always advisable, when making a 180 turn on a course, to pause for a few potatoes to ensure GPS tracking catches you at farthest point.

Not sure if joke but in all seriousness, I think GPS algorithms are good at extrapolating the location of the turnaround even if it didn't record you at the exact point of the turnaround

Longer? Maybe longer by inaccurate readings from gps but not by the official measurement which is all that counts. The additional distance added in the official is undetectable by gps measurements.

The only way to truly know is on race day but many of those 61-62 minute guys in houston got faster at the end and clearly had stuff left in the tank. Jim got about :15 slower for the last two miles. If his optimal pace is mid 5:00s and he tries to stay with a group who’s optimal pace is low 5:00s there is a good possibility he’ll implode regardless of his endurance. I hope he gives us a show but it’s unlikely he’ll be able to run with the likes of Ward and Fauble let alone Korir and Rupp.

"Not sure if joke but in all seriousness, I think GPS algorithms are good at extrapolating the location of the turnaround even if it didn't record you at the exact point of the turnaround"

You think or you know? Because my experience anything with turnarounds displays short on the map from the GPS.

I don't think that you think.

Or anyone in the top 20

Idk I think gps has improved quite a bit, I’ve done long runs on bike paths that are wheeled out and marked every half mile with tree coverage and mines still been spot on.

Shunpo wrote:

Yeah that would be correct if Houston half was exactly 13.1 but we all know it’s not. All certified courses are long. Like I said it equates to 1:03:30 which is great, I really like Jim. It’s the strava trail dorks that crack me up thinking he’s got a shot.

Both courses are certified so they’re both likely a little long meaning you shouldn’t add more than the 250 meters difference like the other guy said.

Show us where anyone that

This thread proves how one REGISTERED idiot can post multiple times trying to convince others something is true when everyone else is telling him he is wrong. Don't have to be unregistered or post under multiple names to be a fool.

anon_hobby_jogger. wrote:

"Not sure if joke but in all seriousness, I think GPS algorithms are good at extrapolating the location of the turnaround even if it didn't record you at the exact point of the turnaround"

You think or you know? Because my experience anything with turnarounds displays short on the map from the GPS.

I don't think that you think.

274m short? No

Shunpo wrote:

Did you even read the post? His time would have been 1:03:30 at Houston. He backed off his mileage for this race and ran hard. Also the guy a minute ahead of Jim had plenty of 115 mile weeks going into this race as well. The point is he’s not going to do as well as his strava fans think.

Haha “115 miles” vs Jim’s 150+ .... so similar ....