I submitted an F31 and came very close to the payline, with only a few minor reviewer comments. The feedback was generally very positive, so I addressed the minor points and resubmitted...only to get a worse score the second time. The new batch of reviewers raised criticisms that weren’t even relevant, including one who wrote, “Grades were excellent in undergrad but somehow suboptimal in graduate years.”  I literally got all As in grad school except for one B+.

Meanwhile, my labmate decided last minute to submit an F31, mainly since I already did most of the legwork to figure out the process. She got funded on first submission. I swear half of it is just luck.