Nathan Yau created this fun and fascinating name guessing algorithm. You select “male” or “female,” the decade you were born, and then type in the first letter of your name. I tried more than a dozen times for people I know and it nailed it on the first letter about 80% of the time. On those that it screwed up after the first letter, it got it right after I entered a second letter. From the project description:
This is based on data from the Social Security Administration, up to 2018. It’s relatively comprehensive, but there are a few limitations. First, it’s data for the United States, so the numbers don’t really apply elsewhere. Second, the SSA doesn’t include names with fewer than five people in a year, so the chart doesn’t cover more unique names. Third, there were no Social Security Numbers before 1935, so the name counts are fuzzier for years before that.
But like I said, the data still has a wide range. I aggregated the annual data by decade and calculated percentages by dividing name counts by total number of Social Security Numbers provided.
Before you enter anything, the chart shows the most popular names for the given sex and decade. Then as you enter a name, the chart shows conditional probabilities. The more information you give it, the stronger the guess.
“Guessing Names Based on What They Start With” (FlowingData)