MileSplit Staff May 01, 2026 PRO See the rest of this article Access the complete article with MileSplit PRO. Subscribe to keep reading Already a subscriber? Log in. Improvement Rankings: Top Delaware Girls 400m marks compared to their season’s best performances from 2025. Most Improved - 400 Meter Dash Comparing 2026 season to 2025 season Rank Improved Athlete/Team Class 2025 PR 2026 PR 1 -12.21 Olivia Wilson Odyssey Charter School HS 2027 1:27.13 1:14.92 2 -10.37 Siara Johnson Newark Charter 2029 1:14.61 1:04.24 3 -8.53 Kayleigh Bristow St. Mark's High School 2026 1:09.14 1:00.61 4 -8.39 Favor Umar Alexis I. DuPont High School 2026 1:17.52 1:09.13 5 -8.06 Micahlena Cotton Smyrna High School 2028 1:03.98 55.92 6 -4.04 ...