The fourth theory I tested was whether cut-offs of at least 2 days resulted in more girls. The result was that shorter cut-offs (2-4 days) favored girls and longer cut-offs (5+ days) favored boys.
Overall, there were 23 boy charts and 36 girl charts with cut-offs, which results in a preference for girls of 61%.
- 2 day cut-off: 13 boy charts, 19 girl charts (sways girl 59.4%)
- 3 day cut-off: 4 boy charts, 11 girl charts (sways girl 73.3%)
- 4 day cut-off: 2 boy charts, 5 girl charts (sways girl 71.4%)
- 5 day cut-off: 3 boy charts, 1 girl chart (sways boy 75%)
- 6 day cut-off: 1 boy chart, 0 girl charts (sways boy 100%)
I also kept track of charts that had a 2+ day cut-off, followed by BD the day after ovulation. (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 14 boy charts and 9 girl charts with this pattern, resulting in a 60.9% preference for boys.
- 2 day cut-off w/BD 1 day after ovulation: 8 boy charts, 5 girl charts (sways for boy 61.5%)
- 3 day cut-off w/BD 1 day after ovulation: 3 boy charts, 3 girl charts (50/50)
- 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%)
This finding obviously conflicts with the expectation that cut-offs and BD a while after ovulation takes place favors girls. However, what I suspect is going on with some of these charts is that the BD on the day after ovulation is taking place within 12 hours after ovulation - which is boy timing. It's impossible to know for sure, of course, without knowing exactly when ovulation or the BD takes place. But I suspect the reason why the results are different from charts where there is just a straight cut-off is that some of the these charts include an O-12.
Cut-offs are one of the most common - and controversial - timing methods for swaying. And one of the most common reasons people give for not believing timing works is that they did a cut-off as Shettles suggested . . . and ended up with a boy.
According to my research, cut-offs are about 60% effective. (I haven't looked at huge numbers of cut-offs, so the percentage could certainly change if I found more charts. However, I have been consistently getting around a 60% effectiveness rate for cut-offs since I started this study, so I think it's on the right track.) A 60% effectiveness rate is GREAT for a timing method. I think it's also pretty great for ANY swaying method period. The highest realistic percentage I've seen for any timing method is 65-70% effectiveness, and there are only around 3 patterns that MIGHT be that effective.
So if cut-offs are really 60% effective for girls, that means it is a great timing method to sway with. However, 60% is far, far, far below 100% effectiveness. It is also below the 75% effectiveness Shettles claimed for girls. It means that if the only thing you do to sway is to have a cut-off, you have gone from a 5 in 10 chance of having a girl to a 6 in 10 chance of having a girl. That is NOT a huge jump in effectiveness. It is definitely not a guarantee of getting a girl, and lots of people who do cut-offs are going to end up with boys. This is why I think it is critical for anyone who is swaying to include as many factors as possible in their sway. I doubt that there are very many swaying methods that are more than 60-65% effective. Doing just one thing - even if it is a very effective thing - isn't going to work that well on its own.
One more notable thing about cut-offs is that they are not a particularly good way to get pregnant. Only 59 charts out of 500 (11.8%) had a cut-off. Only 12 charts (2.4%) had a cut-off of 4 or more days.