I pulled this from the collegetennisranks.com site. Look at pages 7-9. The algorithm could have change from 19/20 but this will give you general idea. Remember players earn points from both fall and spring. There was a MM player last year who did very well at one fall tourney in 21/22-reached SFs of a Regional. Later that player was injured and did not play most of the spring season. I think maybe the player played once and lost at line 3 against an unranked MM player. However that was enough for that player to get in NCAAs '22 tho that player lost 1st round. If you look at the chart of pg 8, players still earn a small amount of points vs nonranked players but get slammed for losses vs unranked. note also that the ITA ranks players up to #175 even though they only publish at most the top 125 single players. A player still receives loss points for losing to a top player but very small compared to losing to an unranked player.
For example, beat a top 5 player-earn 80 points, loss points .1. Beat an unranked player 4 points (1/20 of top 5 win), loss points 1.35 (13.5x top 5 loss) so the hit is much harder for losses vs unranked or low ranked players.
RANKINGS FORMULA Σ(CountWinPts) / (#OfCountMatches + LossPts) Definitely having the opportunity to play ranked players increased the chance of being ITA ranked. Even a win vs ITA 65 is 5x the points of beating an unranked players. Unfortunately there are a significant amount of unfinished matches vs ranked players. Once my son was up a set and tied in the 2nd vs a top 30ish player- he never had a chance to see if he could earn those 50-55 points. The good news is players get to finish their fall individual matches. A player who wants a chance at ITA ranking and/or playing NCAAs singles, should consider the fall schedule of schools that are recruiting him/her and also if the top player in their conference gets an automatic berth at NCAAs-some MMs do, some dont. This also brings up the Fall Nats next week for consideration in that out of the 12 regions, some are stacked with P5s and some are much weaker. Considering that the two finalists from each region get to play at Fall Nats, that does give an advantage to players whose teams are part of a weaker Regional. Also some conferences are spread over 3-4 regionals so their players have more opportunities to reach the finals. For example, the Mountain Regional, only has only Power 5 team Utah. Now the best P5 players are often off playing Futures in the fall so the guys who play 3 or below on a P5 still have a chance to earning a spot in Fall Nats. As I noted in another post, the winner of the SE regional (tough one with Florida, FL State (has one of the highest ranked newcomers), GA) was Blake Croyder who played mostly 5 for GA last year. Two of his teammates qualifed for Fall Nats based on being finalists for AAs so they didnt play singles at the Regional.
Also this has some info https://www.itatennis.co/ita-archives/Assets/ita_assets/ITA Rankings FAQ.pdf