The CGC has 700+ years of history ?
In Chinese, the chart is called 清宫生男生女秘方表. The meaning is something like Qing palace gender selection secret formula. From the Chinese name, there is little argument about Qing dynasty was the time when the CGC invented. As the Qing dynasty started in 1644AD and ended in 1912, so the chart should have less than 380 years of history.
There are many versions of the CGC ?
There is only one CGC. The chart was primarily posted in a Hong Kong Chinese newspaper in the 70s. The chart was not popular at that time as the Chinese believe that herbal medicine is the better way for gender selection other than praying to the Chinese gods. The chart becomes a hit at the western society in the last decade especially in the US due to the popularity of internet and the high accuracy of the chart.
Unfortunately, due to copying mistakes, different versions of CGC are found. Another reason for different versions is due to the fact that some put the mother ages as table column, while some put them as the rows.
The CGChart is different every year !?
Same answer as above, there is only one CGC and we use it every year. However, if we replace the lunar month and mother’s age with western calendar date, the time period will be different every year.
The chart is 99% correct ?
Do you believe that the accuracy of the gender chart is higher than that of the ultrasound scanning? It is impossible. Based on statistics on different website, the accuracy of the gender chart should be around 70~75%, which is actually very high for a free gender predictor.
Actual (western) age and month are used for the CGC ?
This is an easy one! Do you think that the people in Qing dynasty China had used the Gregorian calendar to calculate age and month?
Actual age + 1 = lunar age !?
Depends on the date of birth and the date of the year to measure the lunar age, it could be the same as the actual age, one year or two years greater than the actual age
The chart is equally accurate in each gender period ?
Not true. A longer gender period
gives you a higher hit rate. So it is not surprising that the accuracy of the CGC becomes lower after age 36, as most of the gender period at the older ages are only last for one lunar month.