Under Tack Show Videos and Stride Length Data for Two-Year-Olds in Training

EQUIX advances the Two-Year-Old Sale selection process with this extraordinary video analysis. Each horse's Under Tack is available in a slow motion format giving you a detailed view of Stride Quality, Efficiency, and other key variables that are performance predictors in two-year-olds.

Please SIGN UP above to view our COMPLIMENTARY Under Tack Videos and to check out our Stride Data pricing for each Sale.

What is a ProStride Qualifier?

EQUIX calculates the Average Stride Length and clocks the Gallop-Out times for each horse. Based on the horse’s Average Stride Length and official Under Tack Time, the horses are mathematically Ranked and sorted by Quartile for each show.

Horses that rank in the First and Second Quartile show greater Stakes Winning potential, based on our research since ProStride™ was launched ten years ago.

78% of SWs and 84% of GSWs sold at the juvenile sales have First or Second Quartile Under Tack data.

Our EQUIX ProStride™ video technology will help you select 2YOs whose stride length and efficiency reveal stakes-winning potential. Some of our 2025 stakes-winning ProStride™ data qualifiers include GSWs: Bear River, Booth, Cabo Spirit, Caitlinhergrtness, Cavalieri, Chancer McPatrick, Dream On, Durante, El Potente, Fast Market, Gaming, Governor Sam, Gun Song, Innovative, Irish Maxima, Italian Soiree, May Day Ready, Maysam, Mystic Lake, Nysos, Praying, Pilot Commander, Raging Torrent, Ready for Candy, Shisospicy, Skippylongstocking, Speed King, Taking Candy, Tenma, Usha, Velocity, Vixen, Warming and others. Click on our Stakes Gallery to view recent stakes winners.

Stakes-winning 2yos in 2025 include: Argos, Brant, Bottas, Cy Fair, Desert Gate, Ewing, Explora, Further Ado, Ground Support, Himika, Intrepido, Iron Orchard, Kingsolver, La Ville Lumiere, Revera, Ritzaphena, Sassy C W, Solitude Dude, Throckmorton, Trendsetter, and Yaupon de Replay.

Other ProStride™ standouts include Grade 1 SWs: Adare Manor, Arabian Knight, Arabian Lion, Café Pharoah, Carson’s Run, Cogburn, Colonel Liam, Country Grammer, Du Jour, Eda, Faiza, Gamine, Instilled Regard, Iscreamuscream, Kingsbarns, Knicks Go, Mage, Midnight Bisou, Mitole, Mixto, Muth, Practical Move, Saudi Crown, Speed Boat Beach, Taiba, Varda, War Like Goddess, Win for the Money, and Yaupon.



OBS April Videos Available Now

Raging TorrentNysos

SkippylongstockingTenma

Current Sale VideosFree

  • Slow Motion
    Under Tack Videos of horses in current sale

Per Hip$30

  • Under Tack Show Data on Per Horse Basis
  • Your Selection
  • Avg Stride Length
  • Gallop-Out Times
  • Stride Rank by Quartile








Recent April ProStride Qualifiers
Further Ado won G1 Blue Grass S. at Kee
So Happy won G1 Santa Anita Derby at SA
Saudi Crown won G3 Commonwealth S. at Kee
Yo Daddy won Excelsior S. at Aqu
Tiz Mary’s Comet won Lafayette S. at Evd
Recent March ProStride Qualifiers
Counting Stars won G2 Fantasy S. at OP
Destino d’Oro won G2 Hillsborough S. at Tam
Nu What’s New won G3 Oaklawn Mile S. at OP
Sultana won G3 Orchid S. at GP
Skippylongstocking won G3 Essex H. at OP
Dandona won G3 Florida Oaks at Tam
Explora won G3 Honeybee S. at OP
Goodall won Purple Martin S. at OP
With the Angels won Correction S. at Aqu
Way to Be Marie won Tom Benson Memorial S. at FG
Nine Part won Costa Rising S. at FG
Desert Gate won Hot Springs S. at OP
Mr Mo’s Magic won Sophomore Turf S. at Tam
Recent February ProStride Qualifiers
El Potente won G3 Thunder Road S. at SA
Roll On Big Joe won King Cotton S. at OP
Light Won Up won Sweet Life S. at SA
Coco Connect won Valdale S. at TP
Mystic Lake won Minaret S. at Tam
Yellow Card won Clocker’s Corner S. at SA
Passage East won Barbara Fritchie S. at Lrl
Boss of All Bosses won Edward J. Johnson Memorial S. at FG
Recent January ProStride Qualifiers
Skippylongstocking won G1 Pegasus World Cup Inv. S.
at GP
Destino d’Oro won G2 Pegasus World Cup Filly and Mare
Turf Inv. S. at GP
So Happy won G2 San Vicente S. at SA
Mendelssohn Bay won G3 Firebreak S. at Mey
Margarita Girl won G3 Las Flores S. at SA
Dazzling Dame won Busanda S. at Aqu
Hometown Bound won Turfway Prevue S. at TP
Explora won Santa Ynez S. at SA
Solitude Dude won Swale S. at GP
Thousandsticks won Kitten’s Joy S. at GP




Recent December EQUIX ProStride Qualifiers!
Usha won G1 La Brea S. at SA
Nysos won G2 Laffit Pincay, Jr. S. at SA
Skippylongstocking won G3 Harlan’s Holiday S. at GP
Cabo Spirit won G3 San Gabriel S. at SA
Haqeet won King Saud Bin Abdulaziz Cup at KSA
Caitlinhergrtness won My Charmer S. at TP
Counting Stars won Year’s End S. at OP
Doc Sullivan won Alex M. Robb S. at Aqu
Ms. Bucchero won Sugar Swirl S. at GP
La Ville Lumiere won Blue Norther S. at SA
Complexity Jane won Carousel S. at Lrl
Roll On Big Joe won Ring the Belle S. at OP
Destino d’Oro won Tropical Park Oaks at GP
Counting Stars won Astral Spa Overnight S. at OP
Rising Inflation won LA Champions Day Ladies Turf S. at FG
Sunday Boy won NY Stallion Series S. at Aqu.
Solitude Dude won Inaugural S. at Tam
Recent November EQUIX ProStride Qualifiers!
Nysos won G1 Breeders’ Cup Dirt Mile at Dmr
Shisospicy won G1 Breeders’ Cup Turf Sprint at Dmr
Further Ado won G2 Kentucky Jockey Club S. at CD
Fast Market won G3 Pebbles S. at Aqu
Moonlight won Cherokee Mile S. at CD
Dresden Row won G3 Autumn S. at WO
Sultana won G3 Maple Leaf S. at WO
Roll On Big Joe won Bet on Sunshine S. at CD
Deep Learning won Chelsey Flower S. at Aqu
Throckmorton won Awad S. at Aqu
Complexity Jane won Thirty Eight Go Go S. at Lrl
She’s Country won Key Cents S. at Aqu
Revera won Desi Arnaz S. at Dmr
Rising Inflation won John Valene Memorial S. at FG
Doc Sullivan won NY Stallion Series S. at Aqu
Lookinforbargains won Zia Park Distaff S. at Zia
Alani won Cornucopia S. at Prx