Though more interested in math, our son left BS equally strong in math and writing due to the depth of writing instruction and constant writing requirements, and his grades reflected that balance. Those writing and communication skills served him well in college as he graduated with two published papers, one of which took second place at the IEEE MIT Undergraduate Research Technology Conference his junior year. He writes a mean English paper, too. He’s now finishing up the Army’s Cyber Basic Officer Leadership Course where he is excelling among that cohort of technically trained officers due to his ability to present/communicate solutions, not just solve technical problems. <end of="" brag="" ;)="">
I agree with @Knowsstuff that a balanced school is best, but I always assume that most of the schools discussed on this forum have the ability to challenge and meet most student’s needs regardless of where a student is particularly strong. I would also assume/hope that an applicant would not apply to any known subject-area lopsided school that cannot support the applicant’s main strength and interest. Interlochen, for example, would not be a good choice for a performer who is interested in pursuing an engineering career (those kids DO exist), but Choate might be. It doesn’t appear that the OP is considering such an extreme, though.
For most kids, even those who seem to be math prodigies coming in to BS, most boarding schools will be able to well serve and round out that pointiness if that is a goal. If the goal is simply to play to strength, then choose the school that lays claim to the strength, but my vote still goes to any school that can serve both (balance) but that will encourage the student to work on the weaker area and provide strong instruction and practice in that area because I also agree with @sgopal2 that the best time to learn (and master) fundamental writing skills is in high school. It’s damn near impossible to play catch-up with writing.
(@buuzn03: Was the book you read Malcolm Gladwell’s Outliers discussing the 10,000 hours of effort that leads to a high level of success in whatever that effort is put to? If so, there is a lot of controversy over his use of and conclusions from that data, but it is an interesting read.)