A view of Harvard University in Cambridge, Mass. (Charles Krupa/AP)

The numbers are ruthless: Out of more than 40,000 applications a year to Harvard University, not quite 2,000 make the final cut. Just one admitted for every 19 rejected. Every year high school seniors with straight A’s, perfect test scores and stellar recommendations wonder why they didn’t make it.

Now, the curtains have been lifted on Harvard’s decision-making process. In federal court in Boston, lawyers and witnesses are talking about dockets, first readers, second readers, committees, ratings, dean’s lists and the mysterious factors that influence borderline cases, known as “tips.”

The perennial intensity of competition is the central and undisputed fact behind the lawsuit alleging that Harvard discriminates against Asian American applicants. Harvard denies that charge in the trial that began last Monday.

Some universities draw more applications than Harvard. Two years ago, the public University of California at Los Angeles became the first to receive more than 100,000 bids for freshman admission. New York University, which is private, drew more than 75,000 for the class that entered this fall.

With that kind of volume, giving each application a thorough read is challenging. Here’s how Harvard does it, based on court documents and testimony from William R. Fitzsimmons, the dean of admissions.

First, the applications are divided among 20 groups, called dockets. California has three dockets, labeled A, C and Z. Texas gets Docket D. Virginia, Maryland, Delaware and the District of Columbia supply Docket I.

A subcommittee of four or five admissions officers will read a given docket’s files. A reader will comb through essays, transcripts, test scores, recommendation letters and other information, including race or ethnicity, if disclosed. Then the reader fills out a summary sheet with comments and ratings on a scale of 1 to 4 (1 being highest; pluses and minuses optional) across four “profile” categories: academic, extracurricular, athletic and personal. The personal category is meant to evaluate traits such as leadership and character. The reader will also give a preliminary overall rating, which is a judgment call, not an average of the other marks.

Some files are given to a second reader within the subcommittee, for a second set of ratings. A professor might read a file, too, if the applicant shows depth in performing arts or special talent in a field such as math. Alumni interviewers send their reports. Then the subcommittees meet, review files and vote on recommendations.

From there, files go to the full 40-person admission committee. Cases are weighed. Recommendation lists are pared down. The committee votes on final decisions.

Profile ratings are crucial. Analysis of 160,000 domestic applications across six admission cycles found that more than 55,000 didn’t receive any 1′s or 2′s. Nearly all were rejected. Only about 100 candidates a year receive an academic rating of 1 — even though thousands have perfect or near-perfect admission test scores and grades.

A rule of thumb for an academic 2, as of 2014, was top grades and test scores in the mid- to high 700s (out of 800) on the SAT reading and math sections or at least 33 out of 36 on the ACT. But more goes into the academic rating than scores and grades. Readers take into account the rigor of classes students choose — given what is offered at their school — and what teachers and others say about them.

High ratings are more common for academics than other dimensions: Forty-two percent of applications get an academic 1 or 2, while fewer than 25 percent are rated that high on extracurriculars, athletics and personal qualities.

The university says it values “multidimensional excellence.” What that means, by the numbers, is that a candidate rated 2 across three of the four profile categories is offered admission about 40 percent of the time. But it also wants students with rare talent. Here are admission rates for those given a rating of 1 in only one of the four fields: extracurricular (48 percent); personal (66 percent); academic (68 percent); and athletic (88 percent). The latter figure reflects admission of recruited athletes.

What about plus factors or “tips”? Harvard’s handbook for alumni interviewers says: “Tips come into play only at a high level of merit; the Committee never gives enough of a tip to admit an average candidate at the expense of a first-rate one.”

Among the tips the handbook lists are creative ability, athletic talent and “Harvard and Radcliffe parentage.” That means a plus for children of alumni of Harvard’s undergraduate college (not graduate schools) or all-female Radcliffe College, which merged with Harvard. Data show the admission rate for domestic “legacy” applicants is 34 percent, compared to 6 percent for non-legacy applicants. Children of Harvard’s faculty and staff also get in at higher rates.

Fitzsimmons also keeps a “dean’s list” with applicants of special interest. The director of admissions has a similar list. Hundreds of names get on these lists each year. Some are children of donors. The admission rate for those on the lists — 42 percent — is well above average. Harvard says many children of donors are not admitted.

There are more tips meant to help Harvard assemble an economically and racially diverse class. Children from low-income families get a boost. So do African American and Hispanic applicants in some cases. Harvard says race and ethnicity can be a plus for Asian American applicants, too. The university says race is only one factor among many, using methods accepted by the Supreme Court.

Evidence emerging in the trial shows various racial differences on metrics associated with rating applicants. Asian Americans, for instance, tend to receive higher academic ratings and lower personal ratings than other groups.

The plaintiff, Students for Fair Admissions, contends that Asian Americans are penalized through the rating process and in other ways. Plaintiff’s attorney Adam K. Mortara said Harvard let “the wolf of racial bias in through the front door.”

Harvard denies the charge.

“Is race or ethnicity ever a negative tip?” Harvard attorney William F. Lee asked Fitzsimmons.

“Never,” the dean testified.

U.S. District Judge Allison D. Burroughs expects to issue a verdict after the trial. Her ruling is almost certain to be appealed.