>>537854867
It'll differ for playstyles, but you'll want to aim for useful abilities that you can find on (currently) no more than 3 cards such as Groundwork and Straightaway Spurt, but anything where you get inspired to give you hint discounts and otherwise abilities in cards you wouldn't be running. There are also G1 races in two categories:
-G1s that many umas can do so they build affinity with each other to give you stronger inspirations. Is an uma good at medium and long distance tracks? Then you want them to do the Triple Crown races (almost anything that ends in Sho and the DAAARBYYY) and if they win, that's stronger legacies for future playthroughs. Those sparks will give a green ability hint and a stat boost.
-G1s that focus on giving two stat boosts like speed and stamina. These are races that include Hopeless Stakes, NHK Mile, and URA Finals. https://gametora.com/umamusume/g1-race-factor-list You can check this website for more details about race sparks if you want to pursue them.
