Positioning GPS overlay

es1

RefChat Addict
#7
6.3km in 90 mins, is that correct?

that doesn't seem very far to me! i'll generally average 6km on the line and 10km in the middle and i'm ceratinly not 'as fit as a butchers dog'!

that said you're clearly getting wide and going into the penalty area which are key things to keep doing.
 

JamesL

RefChat Addict
#8
6.3km in 90 mins, is that correct?

that doesn't seem very far to me! i'll generally average 6km on the line and 10km in the middle and i'm ceratinly not 'as fit as a butchers dog'!

that said you're clearly getting wide and going into the penalty area which are key things to keep doing.
What device are you using for those figures?

I agree 6.3.seem on the low side. I average around 8.5-9k per middle (that has really dropped off in last fee games to about 8 but I feel that is down to better positioning) but rarely get over 5k on the line and thats on contrib games. I only did 4.8 on an PL academy game this weekend. I am using a polar v800 with the gps set to high accuracy. I would say I am reasonably fit.

I only ask as I get really sceptical of these tracking devices and how accurate they are. I had a Samsung gear that used cadence as the speed/distance calculator so was not even close to accurate.

Be interested in the device used for this overlay too?
 

es1

RefChat Addict
#9
What device are you using for those figures?

I agree 6.3.seem on the low side. I average around 8.5-9k per middle (that has really dropped off in last fee games to about 8 but I feel that is down to better positioning) but rarely get over 5k on the line and thats on contrib games. I only did 4.8 on an PL academy game this weekend. I am using a polar v800 with the gps set to high accuracy. I would say I am reasonably fit.

I only ask as I get really sceptical of these tracking devices and how accurate they are. I had a Samsung gear that used cadence as the speed/distance calculator so was not even close to accurate.

Be interested in the device used for this overlay too?
i've used garmin forerunner and samsung gear fit 2, and i've been sceptical over distances with both! was using the garmin last year in fitness test prep and it thought i was running 2400m not 2600m!

when i wss wearing it i was running appx 3k per half on the line (contrib) and 5k in the middle on supply games. i've recently been using my s7 (wearing it on my arm whilst running) and it's pretty accurate with distances and speeds, just not best suited for use whilst reffing!
 

Mintyref

RefChat Addict
#10
All GPS devices have a relatively high margin of error especially with so many turns involved. I know of one tale of a runner doing 10k on an athletic track stopping with a lap to go because her Garmin said she'd covered the 10k. Would not have it that her watch could be wrong........4% error!
 
#12
What device are you using for those figures?

I agree 6.3.seem on the low side. I average around 8.5-9k per middle (that has really dropped off in last fee games to about 8 but I feel that is down to better positioning) but rarely get over 5k on the line and thats on contrib games. I only did 4.8 on an PL academy game this weekend. I am using a polar v800 with the gps set to high accuracy. I would say I am reasonably fit.

I only ask as I get really sceptical of these tracking devices and how accurate they are. I had a Samsung gear that used cadence as the speed/distance calculator so was not even close to accurate.

Be interested in the device used for this overlay too?
I’m using the polar M400, I need to have a look at the setting to see how it’s set. I think I’ve set it for 1 ‘ping’ a second. But I agree 6.3 km is on the low side. Not sure how accurate it is
 

one

RefChat Addict
#13
6.3km in 90 mins, is that correct?

that doesn't seem very far to me! i'll generally average 6km on the line and 10km in the middle and i'm ceratinly not 'as fit as a butchers dog'!

that said you're clearly getting wide and going into the penalty area which are key things to keep doing.
Let alone 10km. I am surprised he managed 6.3km without a heart rate.
 

RustyRef

Moderator
Staff member
#14
I used to use a Garmin Forerunner and was doing 11-12 km per game. Switched to a Polar v800 and it dropped by 2km per game. I had the same legs, same kind of games, so obviously one of them was wrong. So I did some research ...

Basically the v800 is regarded as the most accurate GPS watch you can get, and this is because of the sampling rate as it records your position every second. Others are nowhere near this frequent, and rather rely on the fact that you are running in a straight line so they can estimate your course. That works fine if you are running in a straight line, but refereeing has lots of turns and changes of direction so it throws it out.
 

Mintyref

RefChat Addict
#15
Lots of the running GPS devices now sample every second, but that in itself is not a solution, in fact it can introduce more errors! Given that the best accuracy from them is to put you somewhere within a 10 metre circle at every sample, then it has the potential to have a twenty metre error every second.
On a pitch there is also more chance of error because we are even less likely to run in a straight line for any real distance.
 
#16
AFAIK there is no consumer GPS wearable designed to track the kind of movement we do. Common devices are designed for straight lines, constant pace, variation. We do constant pace and direction changes, and go sideways and backwards. No consumer device can be truly (well, remotely!) accurate for reffing.

That said, I can jog pitch markings and they come out ok (Garmin 220). I found some accuracy studies that put most devices in +/- 12% for distance given a course with curves and switchbacks. Based on that my guess is that Polar/Garmin results for reffing might be up to 20% out over short periods. I have no basis for this but a hunch that the "long" duration of games helps to bring average accuracy down.:)

Surely stride length, cadence and speed results cannot be trusted at all!

Conversely, AR results should be much more accurate. My own experience is max speed in line with expectations.
 
#18
Lads - Just a heads up, but there is a product called PlayerTek which is the budget version of the top end GPS stuff that top clubs use. I got mine for about £120 using a discount code and they often do specials to get the price to around that but at the moment it's £150.

It's just a GPS device which sits inside the provided vest which can go under or over clothes. It's deadly accurate, and provides total distance and distance each half, number of sprints, a heat map and a couple of other bits and pieces. All the pro clubs that can't use the real top end stuff use it, and I see no reason why it wouldn't be suitable to also monitor referee performance if that's what you want to do. As it stands the likes of Birmingham City, Celtic use it...it's perfect to be honest. It's picks up your pitch automatically and you just set the location using the map and pitch markings...it's dead easy.

https://www.playertek.com/gb/
 
#19
Lads - Just a heads up, but there is a product called PlayerTek which is the budget version of the top end GPS stuff that top clubs use. I got mine for about £120 using a discount code and they often do specials to get the price to around that but at the moment it's £150.

It's just a GPS device which sits inside the provided vest which can go under or over clothes. It's deadly accurate, and provides total distance and distance each half, number of sprints, a heat map and a couple of other bits and pieces. All the pro clubs that can't use the real top end stuff use it, and I see no reason why it wouldn't be suitable to also monitor referee performance if that's what you want to do. As it stands the likes of Birmingham City, Celtic use it...it's perfect to be honest. It's picks up your pitch automatically and you just set the location using the map and pitch markings...it's dead easy.

https://www.playertek.com/gb/
Yes please. That looks great.
 
#20
I'm heading out now, but I've had it for over 5 months now so if anyone is considering investing the money for one and wants to ask any questions just let me know and I'll reply as soon as I can, but I would never ever dream of wearing a GPS watch or any other sort of product compared to this thing....it's the dogs boll*cks!

I use it for playing, training as well and it's perfect for managing work load and knowing if you hit the amount of distance you wanted to hit in a training session for example or if you play football/ref it measures sprints/high intensity runs at anything over 18kph and also gives you a max speed and stuff.