Oka Sho (Japanese 1000 Guineas) (G1) - Data Analysis

First leg of the classic races for fillies that serve as the battleground for the title of leading heroine
Liberty Island, the winner of the 2023 Oka Sho (Japanese 1000 Guineas), went on to triumph in the same-year Yushun Himba (Japanese Oaks) and Shuka Sho, becoming the seventh Triple Tiara champion in JRA history. In addition, 2024 winner Stellenbosch and 2022 winner Stars on Earth both finished in the Top 3 of the Japanese Oaks and the Shuka Sho of the same year. In other words, the recent winners of the first leg of the Fillies’ Triple Crown have continued to perform well in the second and third legs of this classic series. Let’s now analyze some features shared by successful runners in this race based on results over the last 10 years.

Zero Top 3 finishes for runners backed as 10th favorite or lower
Looking at performances by runners over the last 10 years in terms of favoritism, we find that 17 of the 30 Top 3 finishers were backed as 3rd favorite or higher. Conversely, runners that were backed as 10th favorite or lower were all beaten to 4th or lower. This basically suggests that we can place our trust in highly favored runners. [Table 1]

Runners with three career starts fare well
Looking at performances by runners over the last 10 years in terms of total career starts, we observe that runners with 3 career starts achieved the highest Top 3 ratio, and that 26 of the 30 Top 3 finishers had 3 to 5 career starts. Meanwhile, runners with 7 or more career starts were all beaten to 4th or lower, and runners with 6 career starts achieved a Top 3 ratio of only 7.1%. We should therefore view runners with 3 to 5 career starts as leading contenders. [Table 2]

Most of the Top 3 finishers had also secured a Top 3 position in their previous race
Looking at performances by runners over the last 10 years in terms of finish in the previous race, we note that 26 of the 30 Top 3 finishers had also secured a Top 3 position in their previous race. Conversely, the data show that runners coming off a 4th finish or lower struggled. In other words, runners that performed well last time out should be considered strong candidates. [Table 3]

Lead-up races are a decisive factor
Looking at performances by runners over the last 10 years in terms of their previous race, we find that only runners coming from the Hanshin Juvenile Fillies, the Tulip Sho (Japanese 1000 Guineas Trial), or the Hochi Hai Fillies’ Revue (Japanese 1000 Guineas Trial) delivered three or more Top 3 finishers. However, among runners in this group, runners coming from the Hochi Hai Fillies’ Revue achieved a Top 3 ratio of only 6.7%. We should therefore focus our attention on runners coming straight from the Hanshin Juvenile Fillies or the Tulip Sho. [Table 4]

Seek out the winner!
Focus on runners with several strengths
The last 10 winners all started in Brackets 2-7. We should therefore keep in mind that runners starting in the inner- or outermost brackets have failed to secure a victory. Other shared features among the 10 winners were that they had 6 or fewer career starts, that they had finished in the Top 3 of their previous race, and that they had weighed in at 460kg-499kg in their previous race. [Table 5]

(Masaya Ibuki)