I'll share my perspective on what I feel helped in me getting picked up this last round.
When I first did my panel interviews, it was with the CO & XO of the unit to which I'm assigned. I got high marks on that review, but in the mean time, while dealing with all the administrivia of submitting a packet, the CO served on an IDC selection board.
Since my packet wasn't submitted for a few rounds, I had to "renew" my panel interview and met with the CO again. We spent about two minutes catching up, asking what all was new with me, etc., and then he hit me with it. He said serving on the panel completely opened his eyes to WHO is getting selected, and why. So, here it is.
He said, there are applicants that are "ABSOLUTELY YES", those that are "ABSOLUTELY NO", and then those in-between. (The following exaggeration for effect was his). The "YES" applicants are the congressional endorsement, dad's an ambassador, Medal of Honor-type candidates. When they apply to the board, it's an almost guaranteed selection. The "NO" applicants are the ones that are minimally qualified that recruiters are required by law to submit because they meet the minimum requirements, but when stacked against most others, it becomes apparent they still have work to do to be competitive. All the rest are the ones they have to review and begin racking and stacking. He said, "I don't say this to be mean, but you aren't one of those "ABSOLUTELY YES" applicants, so my job and your job is to get you as close to the top of the list as possible."
We talked about "applying for the job" and making sure that the LoRs and resume highlight not just qualities or contributions, but measured impact.
Consider the following, generalized but still relevant, statements:
"{NAME} is an innovator and proven leader that will excel at being a Naval Officer." (Good...but very generic)
"{NAME}'s innovative approach to solving some of our departments most challenging issues helped to increase efficiency among the subordinates that s/he supervises." (Better...still generic)
"{NAME} pro-actively analyzed three of our department's most challenging issues, developed and tested new methods of operation, then trained the subordinates that s/he supervises, which resulted in a 40% increase in productivity, leading to a time savings of 10 man-hours per week, across the department. (Best)
They're looking for people that will make a positive impact...in whatever way they can contribute. While you may not be able to change your LoRs, you CAN change your resume and it can state measured impact vice generic qualities.
So, I re-wrote my resume, asked one of LoR providers if they wouldn't mind rewriting the letter a little to highlight measured impact. And, submitted to board and got picked up.
Coincidental? Maybe. But, I did what he said would make the greatest impact to my submission packet to get me towards the top, and I got selected. So, there's my one-point data trend.
*Edited to fix a typo.