Reading Our Pedigree Charts

This page is a great starting point for understanding our handicapping reports and the terms we use throughout the site. The sample below is an example Race Index Summary chart.

Race Index Summary

# Horse Sire BM Sire Dosage Profile DI CD GSV Sire BM Sire Reines COI Family
1 ROCKIN COWBOY ROCKPORT HARBOR MAZEL TRICK 3-5-4-0-0 12 5.00 0.92 51.60 27 39.04 3 1.15% 8-f
2 YEAH ROCKY SILVER TRAIN DISCO RICO 5-3-6-0-0 14 3.67 0.93 56.13 27 39.84 7 1.24% 2-d
3 BILLY LION HEART LION HEARTED DARE AND GO 5-2-14-1-0 22 1.75 0.50 63.88 50.77 36.58 18 5.07% 4-r
4 BANCROFT HALL MIDSHIPMAN MR GREELEY 6-6-10-0-0 22 3.40 0.82 55.65 27 48.5 11 1.27% 23-b
5 HOUSE OF FRIENDS INCLUDE BOSTON HARBOR 4-8-10-0-0 22 3.40 0.73 59.84 39.5 44.89 16 2.03% 4-i
6 COURT NOTE WELL NOTED DONERAILE COURT 3-0-6-0-1 10 1.50 0.40 56.72 27 45.46 11 2.10% 3-l
7 TROUBLE WITH GIRLS HELLO BROADWAY ISLAND WHIRL 3-5-3-1-0 12 3.80 0.83 55.89 27 52.37 7 0.66% 23-b
8 THE MAN I AM INVINCIBLE FLYING SPUR 3-2-5-0-0 10 3.00 0.80 52.95 27 27 7 3.12% 7


The racing index charts show up on our pedigree handicapping reports and contain the following fields:

Dosage Profile (DP) - Brilliant - Intermediate - Classic - Solid - Professional
The dosage profile is a series of 5 numbers which shows exactly how many points this horse has inherited from sires in each category. The categories range from speed (Brilliant) to stamina (Professional).

Dosage Index (DI) - A ratio of Speed-to-Stamina. A horse with a DI of 4.0, would mean that he has 4 times as much speed points than stamina points, and would probably be favored in sprint races. A horse with a DI of .25 has 1/4 of the speed as he does stamina, and would most likely be favored in a routing race. The higher the number, the "faster" the horse.

Center of Distribution (CD) - The CD value indicates the "Balancing Point" of the profile, with positive values toward speed. A CD of 0.0 means that the horse as an even number of speed points as he does stamina. A CD of -0.5 means he has slightly more stamina points, and a CD of 1.5 for example, shows a large favor in the speed side of the profile.

Genetic Strength Value (GSV) - The GSV is a 5 generation pedigree rating using racing & breeding statistics from more than 6,500 stallions. The higher the number, the better and it's especially useful in Maiden and Maiden Special Weight races.

Sire (Sire Rating) - This is a rating for the horse's sire. The average value of a sire is approximately 35.0. The higher the number, the better the sire is statistically.

BM Sire (Broodmare Sire Rating) - The broodmare sire (or dam's sire) pedigree rating. The higher the number, the better.

Reines - There have been about 1,000 Reine-de-course mares designated by Ellen Parker ( These mares are influential broodmares from the last 100 years and the Reines field gives you a count of how many show up in the horse's five generation pedigree. The more reines, the better bred the horse is.

Coefficient of Inbreeding (COI) - The COI will give you a nine generation inbreeding rating using Wright's calculation. It can generally be ignored unless you see a number over 5.00%. In that case, there's almost too much inbreeding in the horse's pedigree. A number over 10% indicates too much inbreeding and generally such horses don't do well at the track.

Using the numbers for handicapping

Some handicappers believe that pedigree ratings can be very helpful in handicapping, especially for maiden and maiden claiming races. Dosage can be used to determine the horse's preference for distance and weather the horse is more likely to be a sprinter or router. Horses with high DI values tend to develop earlier than other horses and are more likely to be sprinter types who can handle short distances. Horses with more Dosage Points (DP) are generally better bred than horses with fewer points.

You can use the GSV to find better bred horses. Beware though of horses with high GSV values and low sire or broodmare sire ratings. The horse's sire and broodmare sire ratings are important factors when looking at GSV value and all three should be used in conjunction with each other.

The COI should be ignored most of the time. The majority of horses will have a COI around 2-3% and this generally isn't a problem. The higher is is though, the more of a problem inbreeding is likely to be. Be wary of horses with a COI over 5% and especially cautious of horses with a COI over 10%.

Female family numbers are calculated by looking down the tail female pedigree (dam's, dam, dam, etc) as far back as it goes. Most modern thoroughbred can trace tail female to one of 43 mares that founded the breed. At the end of the 19th century, a man named Bruce Lowe catagories each of these familes and gave the one that produced the most stakes winners the number 1, second most stakes winning family got the number 2, etc. Reasearch later extended this to 73 families and in the 1950's Bobinski updated the family tables and separated each of Bruce Lowe's families into sub categories (family 1 was splint into 1-a, 1-b, etc). There are roughly 200 branches or sub families that are recognized today.

Family numbers are used mostly today to check the accuracy of pedigrees and to classify particularly strong female influences. Some people consider some families to be "sire" families and others to be "broodmare" families. For instance, family 8 is a sire family responsible for producing a lot of good sires and male race horses and they'd like to see colts produced from that family rather than fillies. For instance, a mare tracing to family 1-x will always be tail female to La Troienne which is a really good female family in racehorses. Family 9-c will often go through Lady Josephine and there are other famous mares that pop up in pedigrees all the time.

When you look at the pedigrees on the Pedigree Online site, you'll see the female family numbers for each horse in the last generation displayed in the far right column. You can learn more about female families at the following web page:

Pedigree chart information

ch. F, 1999 DP = 7-0-17-0-0 (24) DI = 1.82 CD = 0.58
ch. 1999
ch. 1990
ch. 1975
$2,393,818 Champion
ch. 1965 [C]
RAISE A NATIVE (USA)   ch. 1961 [B] 8-f
EXCLUSIVE (USA) ch. 1953 10-a
b. 1962
CRAFTY ADMIRAL (USA) b. 1948 8-c
SCARLET RIBBON (USA) b. 1957 23-b
ch. 1985
b. 1977 [C]
NORTHERN DANCER (CAN) b. 1961 [BC] 2-d
SPECIAL (USA) b. 1969 5-h
HIS MAJESTY (USA) b. 1968 [C] 4-d
dkb/br. 1984
dkb/br. 1974 [BC]
BOLD REASONING (USA) dkb/br. 1968 1-k
MY CHARMER (USA) b. 1969 13-c
dkb/br. 1964
BALD EAGLE (USA) b. 1955 4-m
HIDDEN TALENT (USA) b. 1956 21-a
ch. 1975 [C]
RAISE A NATIVE (USA)   ch. 1961 [B] 8-f
SWEET TOOTH (USA) b. 1965 9-c
QUACK (USA) b. 1969 1-w
SAVE gr. 1970 14-b

The line right below the horse name indicates some current racing stats about that horse. The line is read as follows:

[type], [birth year] DP = [dosage profile] (tot points) DI = [dosage index] CD = [center of distribution]

Most pedigree trees will display ancestor information, such as name, country, year born, starts-wins-place-shows, and career earnings.

A red line indicates an X-Factor between generations

A colored box next to an ancestor shows inbreeding. If an ancestor shows up more than once in the pedigree table, you can identify where it occurs by locating the matching colored boxes.

In the first few generations of the pedigree, after the horse's name, year of birth, and color, comes a race record and earnings for that horse. In the pedigree above, Affirmed shows a career record of 29-22-5-1 (29 starts, 22 wins, 5 second place finished, 1 show) with career earnings of $2,393,818.

When looking at a horse's pedigree, there are a few important things you should look for. The first thing we look at in a pedigree is the tail female line. We look to see if the dam raced, won and if she was a stakes winner. A mare with a good racing record is a lot more likely to produce a winner than an unraced mare. In many of our pedigree charts, you'll find the racing records and career earnings. Make sure to take a good look at these. We also look at the female family number (bottom right corner of the pedigree). We give a very slight nod to horses from families 1, 2, 4 & 9. I'd prefer to see a horse come out of one of these families than the others, but it generally won't affect and handicapping decisions.

Make sure to look for bold horses in the pedigree. This indicates that a horse won Grade I race or was a champion. The more bold horses, the better the pedigree, especially when one of the horse's first three dams appears in bold.

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