Thoroughbred Horse Pedigree Database


Frequently Asked Questions

General Questions
  • Why can't I find a specific horse?
  • What kind of horses are listed in's database?
  • Why do some horse names have numbers at the end of them?
  • Help, I'm having trouble printing a pedigree.
  • How do I add a photo for a specific horse?
  • How do I get progeny reports for dams?
  • Pedigree Questions
  • What's the Female Family Query and how does it work?
  • What's the Common Ancestor's Query and how does it work?
  • What are the inbreeding statistics and linebreeding reports?
  • What are the Conduit Mare Profiles?
  • Pedigree Display Questions
  • Display settings options

  • Adding/Editing Horses
  • There's a hole in a pedigree or a horse that I need added? Who can I ask for help?
  • What type of horses are okay to add?
  • I added a horse but selected the wrong parents, can you fix the error for me?
  • I added a horse, but made a typo in its name, now I can't change it.
  • How do I edit the record for a specific horse?
  • How do I add additional information such as color or career earnings?
  • How do I add a photo for a specific horse?

  • General Pedigree Questions

    Q:Why can't I find a specific horse?

    A: Make sure that you've spelled the horse's name correctly. That includes all spaces. If you are confident you have spelled the name correctly and you still don't see the horse, it probably isn't in our database and you'll need to add the horse in order to view its pedigree. Note that even if you add a horse, it may take up to 24 hours for the horse to show up in some of the queries, in others the addition is instant.

    Please note that the database isn't necessarily complete either. We don't have every horse ever foaled, only those that have been added to our database by our users.

    Q:What kind of horses are listed in's database?

    A: The database has been patched together from a number of sources and it has become the largest free online database of thoroughbred pedigrees.

    The majority of recent horses (born after 1990) were added from entry data at various U.S. tracks. Much of the older data for horses before 1990 comes from two different sources. Albin Warth was kind enough to donate a database consisting of 180,000 horses to us in 1999 and that database was combined with our own 60,000 horse database to create a database of around 220,000 horses. Combining the two databases was a difficult process due to Albin's use of roman numerals to deal with duplicate names. As a result, all roman numerals after horse's names have been removed. This explains why some famous horses such as Nijinsky II show up in the database as Nijinsky.

    The remaining horses have been added to the database by the public. In March 2000 Del Mar opened it's pedigree database completely to the public making it very easy to add/edit horses in the database. The result has been very positive and our database is becoming more complete every day. We have hundreds of thousands of horses in the databas and more are being added each day by the public.

    The database also main contain errors and we will not guarantee the accuracy of any information obtained from the Del Mar pedigree query. If you spot an error, we strongly urge you to correct it. If you don't know the correct information, deleting wrong information is better than leaving incorrect information. To help us spot errors it's also urged that you include year of birth (or approximate year of birth) for all additions. This makes it much easier for us to spot problems in the database and correct them.

    Q: Why do some horse names have numbers at the end of them?

    A: To deal with duplicate names the database uses numbers at the end of each horse. For instance Cigar and Cigar2. Sometimes the numbers are removed from the names before being displayed, but not always. As a result, sometimes you see the numbers after names. We feel it's a better method that using Albin's old roman numeral system.

    Q: How do I add a photo for a specific horse?

    A: There are two ways. You can either upload a photo (as long as you have copyright to the photo), or you can link to a photo on another web server (if you have permission to link). For either method, bring up a horse's pedigree, select "Edit Information" from the "Maintenence Menu", and find the "Picture URL" field in the data edit screen. If you have a subscription and are logged in, you will also see an "Upload Photo" button next to the Picture URL box. Simply supply the full URL to the picture on another server, or click the button to upload your own photo.

    Q: How do I get progeny results for dams?

    A: The progeny query works for both males and females. If you don't like the format of the progeny query, then try a 1 generation female family query instead.

    Q: What's the Female Family Query and how does it work?

    A: The female family query can be used to obtain the female family for the horse in question. If you run a 1 generation query you'll get back a list of the offspring for the horse in question if it's a female. When you move up to two generations you'll get back a family listing of the horse's 1st dam. When you increase to three generations you'll get the family of the 2nd dam and so on. Generally speaking you shouldn't need to go beyond 4 generations.

    Q: What's the Common Ancestor's Query and how does it work?

    A: The common ancestors query will let you find all horses in our database that share two common ancestors. As an example, try running the 2 generation common ancestors query for Mr Prospector and Seattle Slew .

    What you'll get back is a list of all the horses who have both Seattle Slew and Mr Prospector within the first 2 generations of their pedigrees. If you refine the query to 3 generations the list will include those horses who have the two horses within 3 generations.

    It usually works better for older horses, horses who don't have any offspring can't appear in other horses pedigrees. You also shouldn't run this query on two horses who are closely related. If you ran the query on Mr. Prospector and his father Raise A Native all you would get back is a list of Mr. Prospector and his offspring. The list would be huge and unorganized which is why I'd suggest using the other queries for close relatives.

    The query is still under construction and within the next couple days, I plan to expand on this query to allow you to filter out horses of a certain sex and horses who have particular sires in their pedigrees. It also needs to print more information about each of the horses returned. For the moment the query lacks these and other features that it will have when fully completed.

    Q: What are the inbreeding statistics and linebreeding reports?

    A: The pedigree query will give complete inbreeding statistics for the number of generations you are currently viewing. The notation such as 4S x 5D lets you know the generation and location in the pedigree that the inbred horse appears. 4S means that the horse appears on in the 4th generation on the sires half of the pedigree. 5D means in the 5th generation on the dam's half of the pedigree.

    Each inbred ancestor is assigned a random color so that you can easily locate the pairs in the pedigree. This is useful for 5 or 6 generation pedigrees. Beyond 6 generations, the color coding is pretty useless because of all the inbreeding that usually occurs. If two colors appear the same, it's totally coincidental and you can get a new set of random colors by reloading the pedigree.

    Also remember, pink squares are used for females and blue squares for males.

    Sometimes you'll also see a lower case 'd' or 's'. This means that the inbreeding is occuring through a female ancestor. An uppercase letter denotes that the inbreeding is occuring through a male ancestor.

    Q: What are the Conduit Mare Profiles?

    A: Bill Lathrop's Modern Conduit Mare Profiles are included in our pedigrees. His system is similar to Steve Roman's Dosage indexes in that it attempts to measure speed and stamina influences in a pedigree. However, it differs from Roman's approach in that it uses female families rather than influential sires to analyze the pedigree. Bill publishes a book about the subject if you want to learn more about it. The conduit profiles will appear below the pedigrees for subscribers to the site only.

    Pedigree Display Questions

    Q: The font is so small, I can barely read the pedigree.

    A: If you find that the font size for the pedigree displays is too small, use the Preferences option to change your desired font size. We recommend 10pt if you find the font too small. You can also change the font size by scrolling down and editing your pedigree display settings. We recommend using the preferences option since that will be a permanent rather than a temporary fix.

    Q: What are the numbers on top of each pedigree?

    A: The numbers you see on top of each pedigree dispaly are related to Steve Roman's Dosage system. For more information about the dosage system see This explains how dosage is calculated and what the various numbers mean.

    Q: What are the numbers and letters on the far right of each pedigree?

    A: The numbers such as 3-a or A1 are female family numbers. For more about female families, I'd suggest taking a look around the Thoroughbred Bloodlines web site. They have a special section on family numbers.

    Q: What do the green stars in the pedigree displays mean.

    A: The green stars are used to denote Reine's-De-Course mares. "Reine-De-Course" is French for "Queen of the Turf". Ellen Parker has done an incredible amount of research on infuential mares in thoroughbred pedigrees and every so often, she does a write up on a new mare and designates a new Reine-De-Course.

    Q: What do the red stars mean?

    A: The Red Stars (*) are used in the pedigrees to show that there's a photo for a specific horse on record. To view the photo of that horse, pull up his or her pedigree and scroll down untill you get to the Additional Information section of the pedigree.

    Q: Why are some horses black and others blue?

    A: Horses whose names are in black type are stakes winners or stakes placed. A horse who is bold and black is one who has one a Grade I race. For older horses who weren't born when there were Grade I races, the bold black type is used to denote horses who won important races in their day...or Grade I equivilents.

    Q: Explain how the X-Factor feature works.

    A: The X-factor is a theory developed by Marianna Haun that attempts to genetically explain large hearts in thoroughbred race horses. It's pretty complicated and rather than trying to explain how it works, I'd suggest buying Marianna's two books: The X-Factor: What is it & how to find it and Understand the power of the X-Factor.

    If you turn this option on when running a horse query, you should see red and blue lines in the pedigree tracing the X-factor gene. Red lines are used to denote single copy horses and blue lines are used for double copy horses. Note that some horses may appear with the X-factor in one pedigree and not in the other. This is because horses that aren't in an X-chromosome passing position cannot pass on the X-factor gene and as a result, they aren't shown. To see where the X-chromosome positions are, click the X-chromsome option on the upper right hand side of the pedigree.

    If you do not see the red or blue lines at all, it's probably because you are using an older web browser. This feature is only supported for newer web browsers. The solution is to update and get a newer browser. The most recent versions of Netscape and Internet Explorer will work.

    Adding/Editing Horses

    Q: There's a hole in a pedigree or a horse that I need added? Who can I ask for help?

    A: You can hit the "Research" link where the hole appears to have a specific horse's pedigree researched. We have a small team of people who can look up pedigree information. When a horse gets added to the Research Request list, it'll show up on the Research Requests page where it'll stay until it gets completed or a week passes and the request hasn't been handled. Generally, it only takes a couple days for requested horses to be added to the database.

    Q: What type of horses are okay to add?

    A: The Pedigree query was designed to allow people to access Thoroughbred pedigrees for horses from around the world. While the system will technically allow you to add other breed's of horses, we'd appreciate it if you didn't add Quarter Horses or other breeds. Adding such horses spoils the intent and purpose of our database. To help people out who have horses from other breeds, we've created a separate Allbreed database.

    If you are interested in using the online pedigree software we've developed for additional breeds or types of animals and would like to fund a separate database, please contact us. The software may be licensed and we can be hired to design and develop a similar pedigree database for purposes other than thoroughbred racing.

    Q: I added a horse but selected the wrong parents, can you fix the error for me?

    A: Please see the question below about editing the record for a specific horse. If you do send me an e-mail with the above problem, I'm not going to correct the error. Instead I will make you correct it on your own so that you'll know how to deal with the problem on your own the next time it happens.

    Q: I added a horse, but made a typo in its name, now I can't change it.

    A: You can't edit a horse's name once it's in our database. What you need to do in this case is add another horse with the correct name and then edit any offspring's pedigrees so that they point to the record of the horse with the correct name. Then it would be appreciated if you delete the incorrect horse from the database.

    Q: How do I edit the record for a specific horse?

    A: To edit the record for a specific horse, first pull up the 4 or 5 generation pedigree of the horse you'd like to edit. Next find and click the "I want to correct the listing or add more information" button below the pedigree and above the inbreeding display. You should then be allowed to edit the record of that horse. Fill in the correct fields and then you'll be given a chance to select the correct parents.