Please Help! How To Calculate Time Using Distance & How To Calculate Dist Using Time

[Dangersteve]

Hi Guys, my first post so please excuse me if this is in the wrong place!

I'm having trouble with a calculation with regards to my UK horse racing timing. In the UK some tracks have sectional times for each horse in a race, other tracks only give the leader of the race, this makes it difficult to then calculate a time for the horses behind in those races by visually assessing their lengths behind and converting back into time. To test my theories so far I use the races which I do have sectional times for each horse and have been trying to find a calculation to 'roughly predict' (within a couple of feet) how far in lengths the horse should be behind the leader, I then visually check that against the video replay to see if it looks correct. The problem is I can get it right for one race but when I apply the same methods to another race the lengths behind can be way off... I think the problem is velocity? Each race being ran at different speeds to the same point. Below I have provided a basic example using a theoretical 2 horse race to try and help explain the problem I'm having.

Horse A (leader) travels from the starting stalls to the 2 furlong pole (2660 feet) in a time of 49.9 seconds.
Horse B (2nd place) travels the same distance in a time of 50.2 seconds.
Horse A covered the distance travelling at 53.31 feet per second.
Horse B covered the same distance travelling at 52.99 feet per second.
A racehorse is approximately 9 feet in length nose to rear.
Horse A ran at 53.31fps/9feet = '5.92 lengths per second' so 1 length = 0.17 seconds
The time difference between the two horses is 0.3 seconds, 0.3/0.17 = 1.76 lengths
SO in theory Horse B should be roughly 1.76 lengths, or approx 16 feet behind Horse A...yet the physical difference watching the video replay looks more like 7 or 8 feet??

If this had been race for example with only the sectional time for Horse A (49.9 sec) available, watching the video replay I would see Horse B is roughly 7-8 feet behind and award Horse B a time of 50.05 (1 length=0.17sec/9(feet length of a horse)*8(distance behind in feet)=0.15). So we now have two times for Horse B, 50.2 and 50.05. The 50.2 is the exact time recorded but yet the physical difference doesn't match the time?

Can anyone please help explain where I am going wrong and how the calculation should look? I'm sure I'm missing another variable, possibly the velocity that they are travelling in? I have checked dozens of races and video replays and in each one the time of a length and the visual distance of a length do not match.

Many thanks!

 

[skipjack]

How are the times measured?

 

[Dangersteve]

In what sense?

If you mean how is the time information gained, then I believe at the racecourses with the new technology, a GPS tracker fitted to the saddle cloth of each horse and it is therefore all done via computer power. In the old days time was calculated as a horse passed furlong marker posts by using a stopwatch or more accurately video replay timers. This is still the case at most tracks in the UK, hence the problem I'm having trying to use lengths behind the leader to calculate times.

The times themselves are in seconds and tenths of seconds.

 

[skipjack]

A horse can run 5 feet in a tenth of a second.

 

[Dangersteve]

Indeed

So if A and B are both running at approximately 5 feet per tenth of a second and B is 3 tenths behind A then visually you would assume the gap would look around 15 feet. If a horse is roughly 9 feet in length nose the rear then the gap should be around 1.6 lengths, or visually it should look like 0.6 from the nose of B to the rear of A. Yet on the video replay the gap looks to be less than a length, B's nose is level with A's back legs. ??? And this seems to be a problem in most races when looking at the distances behind the leader compared to the exact GPS recorded times. Weird!