Blue Stripe and Blue Prize are out of multiple Argentine Group 2 winner Blues for Sale (by 2014 Argentine champion sire Not for Sale), whose fourth dam, Sea Saga, has had a profound impact on Argentine breeding. A daughter of the great French champion Sea-Bird, Sea Saga was one of three stakes-winning fillies produced from the Bold Ruler mare Shama, herself an influential matron.
Sea Saga won only nine of her 55 starts, but she placed another 19 times. Her biggest win came in the 1971 Ladies Handicap, then a race equivalent to a modern Grade 1, and she won two other stakes events and placed in another eight before heading to the paddocks. She lived to produce but four foals, but all were fillies and three achieved some note as broodmares. The most notable of the three was 1977 Test Stakes (USA-G3) winner Northern Sea (by Northern Dancer), who produced Southern Halo to a 1982 cover by Halo. A winner who was multiple Grade 1-placed on the track, Southern Halo rewrote the Argentine record books as a stallion; according to the Stud Book Argentino, he led the Argentine sire list 10 times and the Argentine broodmare sire list 16 times. Southern Halo has also had influence in North America and Australia through his Kentucky-sired son More Than Ready, a champion sire of juveniles in both Australia and the United States.
Blues for Sale traces to Sea Saga through Northern Sea's full sister Dancer's Saga, who won only one of her 13 starts but produced the stakes winners Exclusive Story (by Exclusive Native), Colonial Saga (by Pleasant Colony), and Pleasant Tango (by Pleasant Colony). She also produced the unraced Key to the Mint mare Dancer's Key, whose winning Cure the Blues daughter Key Cure was sent to Argentina. There, Key Cure produced both Blues for Sale and multiple graded/Group 3-placed stakes winner Cure for Sale (by Not for Sale). Another of Key Cure's daughters by Not for Sale, Far Away Eyes, is the dam of Argentine Group 3 winner Far Away Love (by Violence), a filly that ran third in the 2021 Gran Premio Selección (Argentine Oaks, ARG-G1).
Blue Stripe is the latest member of this family to add a notable achievement to her family's story, but she probably will not be the last. Still in production in Argentina, Blues for Sale produced the 2020 filly Blue Coast and the 2021 filly Blue Aura, both by two-time Argentine champion Suggestive Boy, before missing to Equal Stripes for 2022. Blue Prize likewise has foals too young to race, having produced an Into Mischief filly in 2021 before producing an Instagrand colt on March 28. As for Blue Stripe herself, she has at least this season's racing to go before she joins her dam and her sister in the broodmare ranks, where she too may contribute to a saga that links North and South America.