Here is my super-imprecise Speed Ratings guess (Tully wrote a note saying they won't do it, so this is just extrapolating from where I can). The Mayor's Cup this year was run with a few runners also doing Club Cross in roughly the same finishing areas. The two Hacketts (sisters? twins), Marino, Keyser-Gibson and Gong. They rated 141, 139, 136, 133, 132 at the Mayor's Cup.
If we gave the top-rated one of that quintet a 141 at Club Cross, it shakes out thusly:
3 seconds for each speed rating point:
Kaitlin Tuohy 20:06 170
...
Michaela Hackett 21:33 141
Allie Hackett 21:42 138
Amelia Keyser-Gibson 21:46 137
Maryann Gong 22:02 132
Caitlyn Marino 22:04 131.
Granted I'm going off of the Mayor's Cup this year, which Meylan wasn't exactly locked in on:
"Like last year, the speed ratings for this year are a best-guess, making the ratings somewhat uncertain ... I speed rated a couple of recent high school races at Franklin Park, and applied the race adjustment from those races to this race.
Last year, Sydney Masciarelli ran 17:04 (speed rating of 154) breaking Shalane Flanagan's HS course record of 17:08 ... This year, Masciarelli is rumored to have had some recent sickness issues before the race (I have no idea of the effect), but obviously newcomer Margot Appleton ran a super race!"
NOTE: I excluded one common finisher (Catarina Braz-Rocha) who way outperformed her run at Franklin Park (17:32 5K) at Club Cross(20:38) .