There has been some research I have heard in various talks about the range of people's attention spans. Supposedly 30-45 minutes is the maximum for the most attention an adult (so a teen also?) can give to a topic. Content like math can be beneficially done every day, but sometimes, if you were to do two, 2-session - 40 and 40 with ten-minute break - math classes in a week, the break between Monday and Wednesday, or Tuesday and Thursday gives the brain time to process and see patterns. Same for something like science where there needs to be time to contemplate. History may work better on a daily basis because it is usually narrative and biographical.
The thing about saying "11th" grade is there isn't a real reason for why they ought to be studying economics "that" year or ancient or American or world history, or British versus American literature. So... Is it even wise to say that "have" to be in Alg II by that point? I don't know on those accounts. So much of any high school year would depend upon what they had already had. So maybe instead we could build a set of "ideal" content and skills introduced, covered, and mastered from 9th-12th grade?
I would say:
Mastered Algebra I, familiar with geometry, exposed to Algebra II, bonus any higher math exposure (for general education, not "math" kids)
Mastered 3-5 page essay on a work of literature, mastered a 3 page research paper with 3 sources in either science or history
Good exposure to ancient, medieval, British - including Shakespeare - maybe including one enactment, and American literature. Some exposure to other world literature/"modern literature" - like C.S. Lewis, Tolkien, Chesterton. Understanding of what a plot is, understanding of what character arch is, arch types, protagonist verses hero. Understanding in context of various literary devices. Exposure to short, persuasive essays and speeches, poetry.
Mastery of a comprehensive timeline of history where they can plug in any all other content they are exposed to - even math. They should be introduced to the people who discovered or formulated the math they use - it might make it more humane. Working knowledge of ancient- medieval, Renaissance-Enlightenment, and then Exploration-American, and then modern-current events history. Ideally this is done chronologically and the other classes coincide. Government and economics don't have to be a separate class. The most important things about those two topics are not the modern formulae and bureaucracy, but the ideas that shape the two, those coincide with history, and some with literature and even theology.
Science for me is a mixed bag. I am unsure as to why it has to be "biology" "chemistry" and "physics" but that leaves a fourth year for perhaps in depth nature study (for freshmen probably), maybe a semester devoted to local flora and fauna with local guests as lecturers now and then, or classically, astronomy - this would be great during the ancient-medieval history cycle.
I'm sure there are a lot of electives and other things that could be fleshed out and included. But that is what I worry about: that we shove too much "great" content in to a schedule and it comes across mediocre because young minds are ready for the level of the material at the level or delivery and the level of expected retention and comprehension. Generations ago had such a great handle on what could be expected of students, and all of society fit together in such ways as to ensure the preparation and comprehension. Then we somehow got way off the rails. Now we are almost blinded, and lamed in our ability to assess what we ought to be offering, and what they can actually handle.
And in the end students have to "want" to receive, they have to pick up the fork and eat, and have an appetite, a large enough appetite, and then they have to exercise those "nutrients" into their minds and souls. All of that we cannot do for them.
I feel as though most of the time, students these days are doing educational what I did when I was 4 and 5 years old: say I am eating then at the first change feed my food to the dog or hide it under the china cabinet behind me.
And my mom wondered how I was staying so skinny. I wasn't trying to be skinny, I just didn't want that food, or was full.
How do you keep juniors and seniors interested in life-long learning?