@skimom22 SPS has a very competitive Debate Team led by Andrew Gray, agray@sps.edu. They consistently rank in the top 3 in regional and national competitions, and last year had the best ranked individual member of any U.S. school. http://www.sps.edu/page/news-detail?pk=846463&fromId=189016. SPS also offers Civic Honors Program: http://www.sps.edu/page/civics-honors-seminar
Thank you GoatMama! Debate is an important part of the puzzle since I think that is where my DS will find his academic niche. Surprisingly, I do not see debate listed for Deerfield, but I believe they do have Model UN, which is another great option.
@skimom22 you might look at Mock trial for your son as well. Our daughter loves it.
For what it’s worth, most West Coast kids we know who have the choice between Thacher and Cate have chosen Thacher. Both schools are strong, but Thacher is so unique and has such a profound impact on your child’s character that it should be very strongly considered if you have the option. Good luck and maybe my daughter will be your tour guide!
I love Cate, although I obviously l love Thacher more. I have the opposite take as @skimom22. I think Thacher resembles the East Coast schools least. Whether you are talking about the Horse Program or camping program or the California mountain range setting etc, the physical, cultural and community differences are significant. All the Schools you are visiting are great in their own ways. Do your best to assemble a range of options and see what resonates! I think Thacher has the highest yield of any boarding school. When it’s right for a kid, it’s usually right in a big way. Have fun with the process! Also, Thacher admits about 10 boys and 10 girls as 10th graders, maybe 0-2 as 11th graders.
Your child will be challenged academically by these schools no matter whether he starts as a 9th or 10th grader, so I don’t think this is an academic question. It’s really a social, extracurriculars, sports question. Personally, I think there’s a lot of value to the notion of the 4 year experience to give time to develop interests and rise to leadership positions in clubs, etc. With my kids, I encouraged them to take their first year at BS to really adapt to the environment and not overcommit in terms of clubs and extracurriculars. Then try out some of that stuff in 10th grade, and really lean into the things you come to care about the most in 11th/12th grade.
Socially, I think actual chronological age is less an issue than appearance and grade. Just as one small data point, I know a boy who’s quite good looking and a good athlete who repeated 9th grade. He assumed that because he was the age of the sophomore girls, he’d be attractive to them, but to his dismay he discovered that sophomore girls wanted nothing to do with a freshman boy (even if he was the same age as them), and similarly, the freshman girls didn’t want anything to do with freshman boys either!
I didn’t like Thacher. It’s just not my type. But I agree with @ThacherParent. It is quite different from the New England boarding schools. Theschool however seems to like to align itself with the NE top schools in boasting its selectivity and student profiles.
What put you off Thacher?
@magicthecat If you were asking me, for me it’s too small and too isolated, and I don’t like the archeatecture style and dorms. But I understand that to someone else it could be paradise. It really comes down to personal preference.
I completely understand. I am the type that sees it as paradise 
Lol, don’t you love it when Thacher parents say “most kids that I know chose Thacher over Cate”. Huh, I wonder why?
What do you mean? @ThisOneKid
I actually know a lot more kids who go to Cate. Of the kids I know who had the choice, though, almost all chose Thacher. But, they are both amazing schools and kids who have that choice are especially lucky. My daughter could have had an equally excellent experience at Cate. The faculty and facilities are beyond amazing.
Let’s just say Thacher is very “yield conscious”. If it is your fist choice, say it sooner rather than later, repeatedly. Don’t know about Cate. I guess if they do the same, there’d be fewer students who get offers of admission from both schools. There’s another “theory” in explaining what you observed @Kthor626
Yes, Cate is yield conscious and has similar %s to Thacher. I do think that because they’re small schools, they have to be - there’s less “wiggle room”. They definitely get some application overlap (they are only 45 minutes apart from each other so it’s easy to look at both) and I know kids at Cate who chose it over Thacher & vice versa.
My daughter’s experience at Cate has been nothing less than transformative, in part due to the Outdoor Program and the kids/faculty that this unique focus attracts. As we go through the process with my son this year (we looked at 10 schools plus Cate & Thacher) it’s hard not to think that the traditional boarding schools closer to home are really missing something ;-)!!!
Getting back to yield though, I would still caution against telling a school that they’re your first choice. I don’t think that the schools expect it, largely because they know that teenagers tend to change their minds! Revisits were very illuminating, in our experience, and preferences can easily shift. Of course if you’re only applying to one school that’s a whole different story @magicthecat - my fingers are crossed for you!
Thanks @GMC2918 ! I don’t know much about Cate. What’s their “thing”? Or how would you describe the school?
Thank you to everyone for their input. I wanted to follow up regarding the sport’s piece of the puzzle for anyone considering repeating a grade in BS. The rules of sports eligibility are very well defined for California: You have 4 consecutive years of eligibility for HS sports, which begins as soon as you graduate from 8th grade. It is based on 8th grade graduation date, even if you do not start HS immediately or play sports in HS. So, even if you graduate 8th grade at age 10 and then take some sort of “gap year” before starting HS, you would not be able to play sports your senior year in CA. I got this information directly from the CA state governing board for HS sports (can’t remember the exact name, but I googled it and made a few phone calls to get to the right place). This is not the case for most of the states with BS’s on the east coast, but I have not researched every state. It is not a major part of my DS decision, but I thought that others might be interested in knowing this.