# FAQ

## UK Horse Racing's Similar Field Names

This morning I was asked the following to clarify somethings about various field names and other indicators and I think that this is best shared because it may help others grasp how things are reported.

...basically what I am focusing mostly on is the Summary Ratings, focusing mostly on the Cls and WinF columns. Basically if I spot any horse who stands out in any of them especially in Cls, I then open the track pdf file and dig deeper by checking their Class and Weight differentials for the last year cause I think 5 years might not be so realistic. What I am getting confused is that sometimes if for example I see a horse with an underscore of let's say 20 under the Cls column, once I check his Class and Weight Differentials it's a completely different number, why is that and what is the difference between them.

Also I came across a few cases where weight differentials were positive when I dug deeper in the race but when I checked in the Summary rating under the Wtd column it was negative which confused me a bit.

Clearly I need to clarify these issues.

As you may appreciate the ratings here are always evolving. One day an indicator or a field in the ratings may be built and then months or years later new indicators may be built. In fact, new information is being generated all the time.

### WtD and Weight Differential

In the Summary Ratings, which is the sheet that I use the most for my cherry picking, there is the WtD column and in the detailed ratings for the race meeting there is the W.Diff column in the Differentials table. The two show different things. The first, the WtD, is the Weight Delta and has been in the ratings since last century. This figure compares the weight of the horse with the average weight of the horses in the race. So if the average weight of all the runners in a particular race is 10-02 but one horse is to carry 10-05 then it will have a Weight Delta of +3. A horse in the same race carrying 10 stones exactly will have a WtD of -2. The WtD is one of the few indicators, if not the only one, in which biggest is not best.

The Weight Differential looks at the weight of the horse today and compares it with the average weight of the same horse in previous races over the past one, or five, years running on the same race type. If the weight today is five pounds lower than it's average over that period then the Weight Differentilal is +5 (here Big Is Best).

### Cls and Class Differential

The Cls and the Class Differential work in much the same vein. The Class Differential is calculated in the same way as the Weight Differential but the figures used are the race classes of the races over the same race type. The Cls figure tells us how the Model considers that horse in that race. A positive value tells us that the horse has that many pounds in hand to win the race if the race class were the only factor needed to win the race. If the value is negative then that horse needs to find that many pounds of class somewhere to win. Again, Big Is Best.

### Spd and Speed

Spd in the summary ratings and Speed in the detailed ratings are almost related. Spd in the summary ratings was our primitive attempt at calculating speed ratings which was written, again sometime last century. The Speed Ratings (in the detailed ratings) are something which is newer and my attempt to write something on this matter. More work is to be done on these sometime in the future. Because British racing isn't run in the same Drug 'Em and Thrash 'Em way (thankfully) as the American racing actual speed figures based on time isn't valid; at least not in my opinion. So I decided to make Speed Ratings based on how well a horse ran in a previous race rather than time. The Race Rating value, which one finds in the detailed ratings in the form pages, is used for this and, by and large, they do seem to work for all types of racing because, let's face it, when a horse is ploughing through three miles of Plumpton mud it's not going to be particularly speedy and the question is how to translate that performance to a two mile run around Ludlow a fortnight later? So, for the moment the best metric is the horse's Race Rating which it gets after each race.

As time goes on someone may come up with a better Speed rating with the UKHR data and then there will be another set of data. Whether this will happen is a near certainty but when is another question. This will happen I am sure because stuff is always being invented.