Genealogy sites don't give a whole lot of explanation about how to use the match results to find your family. It can be incredibly complex at times. Why? Because DNA numbers can vary greatly based on how much you and your DNA match inherited from the same ancestor. Two people who have the same relationship to you may share very different amounts of DNA. It can sometimes be difficult to even know who your DNA matches are if they have no family tree made and won't respond to your questions. Sometimes there's not even any good matches at all. I'll write about how to deal with all these difficult situations in future posts.
There are times when finding a relative is really easy. I've found birth parents in minutes. Here's an example of an easy case I solved very quickly. Don't get the idea that they are all like this. In fact, most of them are quite difficult. Even with really good DNA matches, it can take a lot of time and research. This one made me laugh because there's an old British phrase, "Bob's Your Uncle," which means, "It's done, complete, we've reached a simple conclusion." Or, "It was a piece of cake." I now find myself saying that phrase every time I solve a mystery like this one...
An adopted woman was looking for her birth parents. She had no idea what the DNA numbers meant. She let me view her matches and I saw a man named Bob with a HUGE match. In his family tree it showed his father's birth year as 1918. Based on age alone it was pretty clear this Bob guy was a generation older than the lady I was helping. When someone is a generation older and has a match that high... Well, guess what... BOB'S YOUR UNCLE! I looked up Bob's name online and found him mentioned in an obituary for his father. It said he had one sibling, a sister. Since Bob is her uncle, his sister is... HER BIRTH MOTHER! I found her on Facebook, and what a surprise, she looked just like the woman I was helping. I found her address, she wrote her a letter and a week later got a response. She was indeed the birth mother. In this case, Bob really was her uncle.
FUN FACT: What's the shortest amount of time I've needed to find a birth parent? Well, technically, about one second. How? An adopted woman was quite amazed when she got her DNA results. What she saw seemed so unlikely, she had me give her a second opinion. Both of her birth parents had also submitted DNA. So, there was nothing to figure out. I looked at the list, and there they were. It doesn't get easier than that. This was extremely rare though. Even seeing one bio parent appear on your list almost never happens. It normally takes more investigation to figure it out. Other than that rare case, I've solved several mysteries in less than thirty minutes. They were similar to the uncle Bob story above. My most difficult mysteries have taken several weeks. I'll write about some of them in future posts.
Sometimes it's not possible to find a family member with your DNA results. The odds are really good that it can be done though. I don't know exactly how many cases I've solved or couldn't solve, but just guessing I'd say I've found at least 80% of the birth parents I've looked for. Sometimes it can only be narrowed down to a family. For example, if there's two brothers in a family and they have no children or grandchildren who've done DNA, I might only be able to say it's one of those brothers. The cases that are usually very hard or impossible often involve a family from a country outside the USA. There are many more people in the USA doing DNA tests than anywhere else in the world. I once tried to help someone who was adopted in Mexico, and another person from New Zealand. They simply did not have enough good DNA matches to find a close relative. If something like that happens to you, keep a close eye on your DNA matches. Maybe someday you will find your "Uncle Bob."
UPDATE: Since sharing this story, I've written several posts about understanding DNA numbers. It's occurred to me that many people simply don't know what a "good" DNA match even means. Be sure to read my articles about understanding centimorgan numbers. I see a lot of easily solved mysteries go unsolved for a long time because no one has bothered to investigate a close DNA match. My posts about family relationships can also come in handy. It's important to know what you're looking for. For example, if you're looking for a half brother, but he's not showing up as a DNA match, don't stop there. What if that half brother had a child. Do you know how to identify a half niece or nephew? Sometimes the answers are right there in front of you, and you may not even know it.
Next, I'll explain why DNA levels over 400cM are so important.