Teaching to the top 25% is both a mindset and a practice that must be done in conjunction with the other 29 best practices. The mindset is that we aim our instruction at the top 25% of the class (so that they will get it), not at the middle or the bottom. The foundational premise of this mindset is the acceleration of learning and high expectations for all students. Instruction is followed by paired activities where the learning continues and students (especially the top 25% of students) teach each other the material. Therefore, the mindset is "aim for the top," and that is what the standard states is the least your students should know.
The practice of teaching to the top 25% comes in the planning and classroom culture. Tailor your planning by cutting out already mastered standards. Teach students that they are not going to learn everything from you (the teacher) in the 15-20 minutes of direct instruction but that they will learn from each other in their activities.
It is not leaving all the students in the dust by teaching way above the whole class's heads.
It is not disregarding your struggling learners. It is trusting your students to teach each other.
It is not teaching page by page from the text book.
Teachers can identify the students that are the top 25% of their class.
Teachers plan their lessons (information, pacing, examples, vocabulary, etc) so that the group of students that makes up the top 25% is engaged and challenged (learns something new).
Teachers use assessments to get information about what students know and can do before instruction is planned.
Teachers do not reteach information from previous grades. Teachers teach grade-level concepts during direct instruction.