Another huge weekend of Texas high school football is on tap, with a trio of top-25 matchups set to go down over the next few days. As teams head to the back halves of their schedules, these games become even more crucial for district playoff seeding — and ultimately their run toward the state playoffs. Below are the four key matchups to watch in the Lone Star State this weekend: The On3 Massey Ratings — which were officially used during the BCS era and have generated college high school sports team rankings since 1995 — rank sports teams by analyzing game outcomes, strength of schedule and ma…