How much of an impact do LORs and essays have on my application?

Answered

According to CV at Top250 colleges , essays count for roughly 25% of the college's admission decisions and interviews about 10%. So together about 35%. The other 65% being test scores 15%, grades 20%, and ECs 30%. So, in general, they are quite important but I personally believe that at Top20 schools like Ivys and Elites, it gets much more complicated as evidenced by how each college weighs and prioritizes various factors and how long their scorecard is.

If you research and evaluate each of the schools you are considering applying to by studying the relative importance of admissions criteria that they disclose on their common data sets you will see that some top schools place a higher value on things than others.

At Harvard for example, the following criteria are given a relative importance of "CONSIDERED"

Rigor, Class Rank, GPA, Test Scores, Essays, Recommendation, Interview, ECs, Talent/Ability, Personal Character, Volunteer Work, Racial/Ethnic identity, SAT/ACT essays (last cycle).

At Stanford, they think everything I've listed is "VERY IMPORTANT" except for the category of Interview, Racial/Ethnic, Volunteer work which has a "CONSIDERED" value.

At MIT, only Personal Character is "VERY IMPORTANT", Rigor, GPA, Test Scores, Essay, Recommendation, Interview, ECs, Talent/Ability, SAT IIs (last cycle) are "IMPORTANT" and Class rank, Racial/Ethnic, Volunteer Work, and SAT/ACT essays are "CONSIDERED"

So not only do T20 schools have more criteria than 5 mains ones but more like 13 main ones, but each of them put a different relative importance on each of the main criteria.

But in reality, I can tell you that Stanford, MIT, and Harvard have very complicated scorecards which have up to a 100 or more criteria on them. If you want to learn more about the Stanford one, then watch some youtube videos on various admits who have requested to see their admissions file. They break down what the Stanford scorecard and what they scored.

On a cursory level, I can with confidence say that the essay/interview will not count for 35% of your admissions criteria at any top 20 colleges. It might be 15% tops.

That being said will your 1-11% magically jump from a hard reach to a target if you have a great essay and interview. Not so much because most of your peers vying for the same spot are competing with you and are all going to spend a lot of time prepping for their essays and interviews.

I applied to Stanford last cycle with a 30%-40% and did not get accepted. My guess is that I didn't excel at intellectual vitality. I'm sure I scored mostly 2s on everything else. One of my friends got in and it's clear that she fits more than what Stanford was looking for. She coded, built an app for COVID-19, took Calculus III and Linear Algebra, Differential Equations, was on the robotics team and a State level Violinist. I certainly had more leadership, volunteering, community service, honors and awards but it was clear to me that Stanford likes very STEM'y people versus humanities types that are trying to save the planet and humanity.