Case Study: Buying Broodmares & Selecting Stallions


Buying Broodmares & Selecting Stallions

Buying Broodmares

broodmareThe annual breeding stock sales are by far my most favorite to prepare for and to shop. The quest to find the perfect broodmare in hopes of breeding a future champion. Easier said than done!

Stop dreaming and get focused! That’s what I must continually remind myself. That said, I would like to share a glimpse at my process of selecting broodmares from a sales catalog and how I select stallions for them.

I have a minimal set of criteria that I like to use. There’s nothing set in stone, but it filters out the plethora of options and keeps me from chasing shiny commercial objects.

The very first thing that I do is focus on the female families that will be contributed by the broodmare sire. I want to see that two quality racing families are coming forward. This is in reference to Female Families 1, 2, 3, 4 & 5. For a refresher course, please read “Are Female Families Really That Important“.

Because I constantly walk a fine line between quality and value, I was the underbidder on this mare at the Keeneland November Sale but I will use her as my example. Most pedigrees don’t set up this well and I was prepared to swing for the fences on her.

In review, whether breeding or buying a racehorse prospect, I want to see at least one sire female family and four racing female families of the eight families represented in the third generation. Focusing on broodmare sires first with two racing female families built in gets me there that much faster. Let’s look at Dalsaros’ sire, Unbridled’s Song:

Notice the 1 & 4 families that will be contributed. Unbridled’s Song is just one of the great broodmare sires that fit this scenario, including 2020 Top 100 Broodmare Sires Sunday Silence, Tapit, Street Cry (IRE), Bernardini, Malibu Moon, Pulpit, Montjeu (IRE), Harlan’s Holiday, Mineshaft, Dixie Union, Sadler’s Wells, Yes It’s True, Wild Rush, Kitten’s Joy, Sky Mesa, Repent, Scat Daddy, Congrats and Dixieland Band. Regardless of the methodology, that’s an incredible list to focus on.

After I filter for all mares that are by all similar stallions fitting this profile, I shift my focus to each individual mare. The following criteria must then be adhered to:

  • Must be a winner of reasonable quality.
  • Must be a half- or full-sister to a stakes winner or graded stakes placed runner.
  • Must be in-foal.
    • I’m looking at 2-for-1 value here.
    • In most cases, I seek to resale the resulting foal for 80% of the total purchase price.
  • Must be eight years old or younger at the foaling of the in-utero foal.
    • Most broodmares tend to produce their best runners within the first two foals.
  • Must have an April or earlier last cover date.
    • I don’t enjoy holding an empty mare for an entire year due to late foaling.

Since I am looking for mares that are in-foal, the covering sire is another determining factor. Sales price is very much dictated by the covering sire. However, I prefer covering sires that have proven to produce racehorses and still have commercial value. I will take a gamble on unproven sires if they are commercial enough, especially if they produce an OPTIMAL Mating with the mare. At the end of the day, we want quality racehorse production out of our mares from the beginning.

Such is the case with Dalsaros in-foal to City of Light. A young unproven stallion that is commercial and has good weanlings on the ground that are selling well. Here is what the 2021 City of Light – Dalsaros pedigree looks like:

Notice where we started with Unbridled’s Song bringing forward the 1 & 4 families. All Unbridled’s Song mares will have this, thus his consistency as a broodmare sire. But, Dalsaros’ dam, Ask the Moon, brings two more quality racing families (2S & 2D) forward, too. So, if the goal is to have at least one sire family and four running families built into the third generation of a foal, we are way ahead of the game with Dalsaros! All she needs from a suitable stallion to complete the family equation is one quality sire family.

Sire families are represented by 3, 8, 9, 11, 12, 13 & 14. City of Light not only adds two quality sire female families (13C) but adds two more quality race families (2:O & 2E).

We can talk theory, broodmare sires, nicking, commercial value, etc. all day, but if the mare’s physical is not acceptable then we have nothing else to talk about. On to the next horse!

Dalsaros is a phenomenal physical, has a great walk and is in foal to a stallion that produces an OPTIMAL Mating. Plus, plus, plus! Satisfying the female family equation is just a starting point for what I look for overall. All other factors must be met.

OPTIMAL Mating Analysis

Horses bred on OPTIMAL Matings have proven to possess more potential to become superior racehorses. In fact, most will break their maiden in the first two starts. Combined with a good physical, good vetting and a price that falls within a budget, OPTIMAL Matings help to focus on buying or breeding better racehorses.

OPTIMAL Mating Factors for 2021 City of Light – Dalsaros foal

  • Outcross Percentage = 78% (OPTIMAL >= 70%)
  • Linebreeding Balance = 3 (OPTIMAL <= 10)
  • 2nd Generation Linebreeding Balance = 11 (OPTIMAL <= 17)
  • Grand sire/Grand dam Pair Percentage = 3% (OPTIMAL <= 17%)
  • Gender-balanced Linebreeding Difference = 2 (OPTIMAL <= 2)
  • Number of Dominant Runner Female Families = 6 (OPTIMAL >= 4)
  • Number of Dominant Sire Female Families = 2 (OPTIMAL >= 1)

NOTE: All 7 factors are met.

Key Linebreedings

  • 5×5,5 Mr. Prospector – gender-balanced through sons Gone West & Fappiano and daughter Macoumba
  • 6,6×6,6 Raise A Native – through sons Mr. Prospector and Alydar
  • 6,5×6 Secretariat – through daughters Secrettame, Sister Dot & Weekend Surprise
    • Including
      • G2W Smooth Like Strait (Midnight Lute)
      • SW Edwards Going Left (Midnight Lute)

Selecting Stallions

Finding the right broodmares for the right price is a monumental task. But, when I’m fortunate enough to get the right mare, I don’t want to waste a year by breeding her to the wrong stallion. I’m looking to breed the best racehorse possible based on an OPTIMAL Mating, physical compatibility and maintaining commercial appeal. Here is the OPTIMAL Mating Summary prepared for Dalsaros:

All five stallions listed are OPTIMAL Matings, but I would lean towards Nyquist because:

  1. Good physical compatibility to Dalsaros
  2. Commercial enough to produce a profit if selling
  3. Greatly improves his mares, even those of high quality.

OPTIMAL Mating Factors for Nyquist – Dalsaros mating

  • Outcross Percentage = 80% (OPTIMAL >= 70%)
  • Linebreeding Balance = 3 (OPTIMAL <= 10)
  • 2nd Generation Linebreeding Balance = 3 (OPTIMAL <= 17)
  • Grand sire/Grand dam Pair Percentage = 13% (OPTIMAL <= 17%)
  • Gender-balanced Linebreeding Difference = 1 (OPTIMAL <= 2)
  • Number of Dominant Runner Female Families = 4 (OPTIMAL >= 4)
  • Number of Dominant Sire Female Families = 2 (OPTIMAL >= 1)

NOTE: All 7 factors are met.

Key Linebreedings

  • 6×4 Caro – gender-balanced through son Siberian Express and daughter Trolley Song
  • 6×6 Secretariat – through daughters Terlingua & Weekend Surprise
  • 5X5,5 Mr. Prospector – gender-balanced through sons Seeking the Gold & Fappiano and daughter Macoumba

This methodology of buying broodmares and selecting stallions may seem strict and extreme. Because, it is! The great thing about this approach is that it’s totally scalable regardless of your budget.

Stallions get hundreds of opportunities to produce quality racehorses every year. A broodmare only gets one shot if all goes well. Don’t waste the opportunity of breeding a quality racehorse first. Challenge the commercial status-quo! Breeding to race is commercial!


Whether you are new to the game, experiencing more losses than wins or just looking for a new approach, I am confident that I can help you breed or buy a better racehorse. To find out more about OPTIMAL Matings and how they can help your program, please subscribe to my Blog/News page HERE to receive future information on complimentary mating recommendations, sales short lists, stakes winner pedigree analysis, news on personal client success and any other random thoughts or ideas that I may have. Also, receive a complimentary copy of my report “Blind Luck or Designed Luck? – How A Kentucky Derby Winner Was Bred” sent directly to your inbox.

For inquiries or more information about Shepherd Equine Advisers, please contact Clark Shepherd at 859-321-6618, or by email at

I would love to hear any comments or questions that you may have. Please submit them below. Maybe we can address them in a future post!


I offer my expertise as a bloodstock agent, sales consultant, and pedigree analyst to assist in breeding or purchasing superior thoroughbred racehorses through sound pedigree principles, horsemanship, and consistent implementation of well-designed plans. To find out more about how my services can help your program, please contact me at 859-321-6618, or by email at

4 thoughts on “Case Study: Buying Broodmares & Selecting Stallions

  1. Thank You Clark,
    My open mares, Dixie’s Comfort (Dixie Union), Indian Sugar(Congrats), her 4 yo maiden close to debut with works at Belmont, and a tall maiden Fairbanks mare out of Tanwi Springs, Sweeter Surprise, bred by Jonathan Shepherd. I’ll do a partner with a Ky season to marketable stallion if you find the mares worthy. I’ll sell the mares in foal, (not Indian Sugar), weanlings and yearlings in partnership, out of proceeds, foalshare… or 50/50.
    I brought home a yearling colt unsold from Keenland, going on with him limits stud fee availability in 2021 this coming season, Just fishing. Thank you for your time, expertise and friendship!
    Peter Alafoginis

    1. Thanks for reaching out, Peter! Bringing horses home after an RNA is no fun. I totally understand your situation. It usually takes several hours to do a comprehensive OPTIMAL Mating for any given mare. I typically do this on a complimentary basis in return for initiating the contract with the stallion farms. They then pay me a commission if/when the mare foals and stud fees are paid. I greatly appreciate your offer and would love nothing more than to help you but I must decline given the scenario that you proposed. Thank you for the opportunity and best of luck!


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