After looking at another 200 charts, cut-offs still favor girls - but the effectiveness rate for cut-offs has decreased.
Overall, there were 34 boy charts and 48 girl charts with cut-offs, which results in a preference for girls of 58.5%.
- 2 day cut-off: 19 boy charts, 25 girl charts (sways girl 56.8%)
- 3 day cut-off: 7 boy charts, 15 girl charts (sways girl 68.2%)
- 4 day cut-off: 3 boy charts, 6 girl charts (sways girl 66.7%)
- 5 day cut-off: 3 boy charts, 1 girl chart (sways boy 75%)
- 6 day cut-off: 2 boy charts, 0 girl charts (sways boy 100%)
- 7 day cut-off: 0 boy charts, 1 girl chart (sways girl 100%)
Short cut-offs (2-3 days) have a 60.6% effectiveness rate overall, and 3 day cut-offs appear to be the most effective at 68.2%. However, part of the reason why 3 day cut-offs may appear to sway more for girls is because a "2 day cut-off" on the FF charts may really be a less than 48 hour cut-off - if BD took place in the evening and if ovulation occurred in the morning. I still think a 2 day (that is, 48 hour) cut-off is a good timing method.
I also kept track of charts that had a 2+ day cut-off, followed by BD the day after ovulation. (Again, please keep in mind that this is NOT the same thing as a cut-off and an O+12. BD the day after ovulation may mean an O+12 - but it may also mean that the BD happened within 12 hours of ovulation if ovulation occurred late in the day on the "day of ovulation," or it may mean the BD occurred long after the egg had died.) There were 20 boy charts and 10 girl charts with this pattern, resulting in a 66.7% preference for boys.
- 2 day cut-off w/BD 1 day after ovulation: 11 boy charts, 6 girl charts (sways for boy 64.7%)
- 3 day cut-off w/BD 1 day after ovulation: 6 boy charts, 3 girl charts (sways for boy 66.7%)
- 4 day cut-off w/BD 1 day after ovulation: 3 boy charts, 0 girl charts (sways boy 100%)
- 5 day cut-off w/BD 1 day after ovulation: 0 boy charts, 1 girl chart (sways girl 100%)
Alas, while these are some of the highest effectiveness rates I have found for boys I cannot recommend a cut-off and then BD the day after ovulation to sway for a boy, lol! The reason, of course, is that I don't know exactly when ovulation is occurring or when BD is occurring so I don't know WHY this pattern is producing such a high rate of boys. What it may suggest is that BD within 12 hours after ovulation favors boys if the most recent previous BD took place 3-5 days before. This would fit with other scientific evidence discussed on IG. But that is the best hypothesis I can come up with to explain the pattern.
One more notable thing about cut-offs is that they are not a particularly good way to get pregnant. Only 82 charts out of 700 (11.7%) had a cut-off. Only 16 charts (2.3%) had a cut-off of 4 or more days.