How to Use One-to-Many Matching

(00:00):
Many people take a genealogy DNA test to find cousins. And if you’re using the Genesis system of GEDMatch, you can find cousins by using the one to many tool.

(00:17):
Howdy, I’m Andy Lee with Family History Fanatics and this is a segment of dna. In this series, I am going over all of the different tools on the new Genesis system of GEDMatch and today we’re gonna be talking about the one to many tool. So when you log into Genesis, the one to many tool is going to be down here under DNA applications. And for those of you who do not have a tier one membership, you still have access to this tool. There are actually two tools right now and they’re each a little bit different, so I’m going to show both of them. But first what I wanna show you is that you manage kits over here in your DNA resources and by clicking on any one of these kits, it’s going to go to the one to many tool. So just like that it will pull up the list of matches for that kit.

(01:10):
So let’s go back and let’s actually use this one to many tool and we’re gonna start with the one to many comparison result. And this is the simpler of those two tools. Now what it’s gonna have you do is it’s gonna have you enter a kit number. Now this can be one of the kit numbers that you manage. It can also be any other kit number that is publicly available. So this is the quick table that it will give you for a one to many comparison. And let’s just go through each of the columns so that you understand what information is being displayed here. So first off is the kit number column and that is just the kit numbers for the kits that you match. And each one of these is hyperlinked. If you click on them, they are gonna open the one to many tool for that kit number.

(01:55):
So you can actually jump from kit to kit to kit all the way through as you’re looking at this different information. The second column is one to one, and this is actually a tool to do a one-to-one comparison between your kit. And that’s listed right up here with this kit that you’re doing the one to one comparison to. And what it’s gonna do is it’s gonna open up the one to one comparison form. I will be covering that tool on another video, but if you want to try it out, go ahead and try it out. Now the next two columns are the name and the email and this is the information to identify that kit number. Many people in the name field, they actually use an alias, but the email is the email contact that you can use to contact the person that manages that kit.

(02:4o):
Now, one thing to remember is that as you can see here, a lot of people manage multiple kits. And in fact, if you come up with dna@lead-web.org, that means you match one of my kits. But I have a ton of kits for not just my personal side of the family but also my wife’s side of the family and also for some other people that I manage kits for. So don’t assume that the person that you’re matching with is the person that’s gonna be answering the email. Make sure whenever you email somebody you include that kit number and that alias because it may not be the person that’s answering the email whose kit you match, it may be somebody else. So the next column is called the largest segment and this is the largest segment in centimorgans that you share with that person. Now with the top of the list here, it’s going to be a, you know, fairly big number if you have very close relatives.

(03:36):
As you go down further in the list, what you may find is that the amount of centimorgans that you match is the same as the total centimorgans and that just means that you match on just one segment. So the next column is the total centimorgans. And in this column it is telling you how much total shared DNA you have. And this is usually a good identifier of how closely you’re related. In some cases you can actually identify what that relationship is just based on the amount of centimorgans that it’s showing. The next column here is the generations column. And this is an estimate of how many generations removed the two of you are. In other words, how far this kit of this person is to this next person. Now a 1.0 relationship is going to be either a twin or your parents.

(04:32):
When you get further away it will go to grandparents and then aunts and uncles at about 1.5 and then cousins, first cousins at about 2.0 and it continues on by the time you get to about 4.0, 4.5, it’s really not a good predictor of how closely you’re related other than the fact that hey, you’re at least four generations removed, but it could be a lot further away and that’s just because the amount of DNA you share is not very large and there’s lots of different relationships that overlap with that amount of dna. The next column is the overlap column. And this is an interesting one cuz this is part of the reason why Genesis was created. Now you can see with a lot of these right now it says NA and these were all kits that were uploaded into the old Gedmatch system. And so they were initially analyzed using the Gedmatch algorithms.

(05:23):
But as you go down your list, you’re going to come across some that have a number and a color highlighted. What the overlap is is it is the number of snips that is being used to compare these two kits. Now the more snips the better. So in this case this is read and it says it’s 50,000 snips and that means it’s not necessarily a really good comparison but it’s still able to compare. Whereas if we go down a little bit further we can see that hey this one has 133,000 snips being compared more than twice as much as that other kit and it doesn’t have a color at all, which indicates that yeah, this is a much better comparison for it, it’s probably much more accurate. So the next column here is the date compared, and this is the last time that these two kits were compared.

(06:11):
Usually, when a kit is upload it’s going to be compared during processing to all of the other kits as far as finding its matches. So in some of these cases you can see that these were back in 2018 and this is probably when they were doing this initial genesis crossover With some of these newer kits you can see that hey, this was done back in 2018 in December, so most likely this kit was uploaded in December of that year. Finally the last column is the testing company. Now previously GEDmatch used the first letter of the kit number to indicate the testing company, but since then they have gone to just a random two characters for the first. And so they’ll actually tell you the testing company over here. So for old GEDMatch kits you have to know that M is 23 and me A is ancestry, T is family tree dna and H is my heritage with the new system for all the new uploads you can see right here, hey it’s gonna tell me exactly that this is 23 and me and you can see over that the kit number, it has two letters as the first two digits.

(07:17):
So it is a little bit different as far as the nomenclature for the kit number. Now something else to be aware of as you’re going down is you’ll see every now and then that some of these kit numbers will be highlighted in a green and sometimes it’s a darker green, sometimes it’s a lighter green. What that indicates is that indicates that this is a new kit. You can see that this one was probably just uploaded, in the end of March. But if I scroll down here I can see that this one right here that’s light green, it was uploaded just about a week, two weeks before that. And so it’s a lighter green. What Genesis is doing is it is looking at the last 30 days to see what new kits are available. So if you periodically want to be looking at your GEDmatch list and see what’s new, what you should be doing is once a month go in and look for these green kits which indicate that that is a new kit and you can add those to whatever match list that you organize somewhere else or take a look at them in more detail.

(08:16):
Now one thing you will notice with this tool of the one to many matching comparison is that there’s not a lot of customization that you can do. There is not a sorting of any of these columns or, being able to move things around. And so what you need to use for that is you need to go to the other tool. Now the other tool is called one to many the beta and that means that there’s still some bugs that they’re working out, still getting the final programming finished with it. But I’ve used it several times and I find it very useful. So feel free to give the one to many beta a try and we’ll go through what is different about that. So first off, when when you click on it you can see yeah this is a completely different user interface that you’re seeing.

(09:00):
We’re gonna put our kit number in here at the top and then we’re gonna filter by either autosomal X in this case we just wanna do autosomal and then it has this offset. We’ll talk about that in a second. It tells you, well what size do you want? And then whether you want tag groups, what the overlap cutoff is for right now, I’m just going to search and so I get a match list and you can see that hey there it’s a little bit different. There’s actually some different columns in here, some more information and there’s some other things that we can do. Now this first column is the select column and this is for visualization options up at the top here. Now it’s only available to tier one customers. And so right now you can see that it gives me an X that I can’t select any of these boxes.

(09:51):
But next column is a kit number and that’s what I just described before. It is the kit number and if I click on this, then it’s going to go to the one to many for that kit just like the other one did. Then we have the information, the name and the email address. And again that is the same. Next we have a new column, the GED or Wiki tree. And as you go down here you can see that some of these have either GED or, and I don’t have it listing Wiki tree on any of these. What this is is this is a link to a GEDcom file so that you can actually see how that person is related based on what they’ve uploaded as far as a GEDcom And I’ll go over GEDcoms in another video. The next column is the age and this is how long that kit has been uploaded.

(10:42):
So taking a look at some of the kits that I manage right here, you can see they’ve been uploaded for you know, 3, 4, 5 years, six years in some cases because that’s how long it’s been since I’ve been on the GEDmatch website. Others of these have only been uploaded for a few months or in some cases you’ll find just a few days. Now let’s column this type. And this is actually something new to me and I am still trying to figure out what this is. I might actually have to email the GEDmatch programmers to figure out what type is most everything that I’ve seen is a two. So when I have some more information on that, I’ll be able to give it to you. Then we have the sex of the person, whether they’re male or female. And this is reported by the person that uploaded this kit as is the next two columns, which are the haplo groups for your mitochondrial DNA or for your Y dna.

(11:31):
And again, these are all self-reported by that group. So some of ’em may be incorrect, some of them may be outdated in some ways. Then we get to the total centimorgans and this is the total amount of shared DNA that you have with that person. Then there is the largest centimorgans. And again, this is the same as what we saw in the other tool, but the difference now is as you can see, each one of these is hyperlinked and that’s because that one to one tool is now that hyperlink. So that hyperlink will go to that one to one comparison, the generations columns next and that is the same thing. And then we also now have the XDNA. So the beta version is reporting not only the autosomal DNA that you share but also the XDNA that you share with those people.

(12:22):
There is the source, which is again what company that kit was from and of course the overlap how much overlap there is between those two kits. Now with this format there are some different things we can do. You’ll notice that in each one of these columns you can actually sort by alphabetically or reverse alphabetically. So you can look at the kits in an alphabetical fashion if you wanna look at the ages. So you wanna see what the most recent one is, you can look on that or if you wanna see the oldest one, you can do it that way. If you want to just look at all the ones that have a GEDmatch or a tree, you can click on that and it’s gonna bring all those to the top. Again, with the total cm, that’s gonna be either all at top or all at the bottom.

(13:09):
If you’re just looking with Hapla groups and you want to group those together, then you can click on the Hapla group and that’s going to group each of the call to Hapla groups together. And another one that is important is XDNA. If you’re looking specifically at XDNA matches, it’s gonna be able to pull up those matches that you share XDNA with. Now with this beta version, there are also some other tools and we can go back to the top, we can actually see this and we’re gonna change some of these around and we’ll see how the list changes. So first off, I’m gonna start a new list and it is 1 – 50. So this is just looking at my matches number 1 – 50. So the first thing I can do is I can go up to this limit and I can change that limit.

(13:54):
So let’s say that I want to look at my top 100 matches. Well now I have a hundred matches and for the free side you can actually look up to 3000 matches. Now 3000 matches is for most people going to be plenty of information that you need. What we can do is we can go over and see at my three thousandths match how much centimorgans I’m sharing with them. And all the way down at the bottom you can see at 3000 I share roughly 9.90 centimorgans with those people. So the next thing that we can do with this list is we can start at an offset. So let’s say for instance that I’m looking at this list and I’ve already looked through all of my first top 100 matches and I want to just be focused on the next set. So what I can do is I can put 100 in the offset, that means it’s gonna start at my 101st match rather than my first match.

(14:57):
And it’s going to look for the next 100 matches. So this is my 101 to 201 matches and I can change these numbers based off of anything within here as long as I don’t go above 3000. Now the next thing that I can do is I can change what the limit is. So for instance, if I change this to a higher number, then that will eliminate those matches that only share a smaller segment of that. So how could you use this? Well, I’m going to look at my 500 matches and let’s say of that top 500 matches, I know that I have a lot of endogomy and that is where we have um, family members, not necessarily close family members, but second, third, fourth, fifth cousins that are intermarrying all the time. And so you end up looking like you share a lot more DNA than what you really have.

(15:54):
And what it does is it means that when you start to look at your match list, you have thousands and thousands of matches that are all these small, you know, 10, 15 centimorgans, but they’re really, really distantly related to you. So by changing this and let’s say I’m gonna change it to 20, then it’s going to look at everybody that has more than 20 centimorgans shared. So you went, so you can see that that match list went from 500 people down to just 143 people because these people all have to share at least 20 centimorgans or more. The next one is tag groups. Now if you have tag groups, you may have made them a different color. Now I don’t actually have any tag groups tagged on this account right now cause I’m gonna show you how to do that in another video. But what this will do is it will actually bring the groups up to the top so that you can focus on any of those tag groups. Now finally, the last tool here is the overlap cutoff. And if you remember I said that the more overlap you have, the better it is for a match. So if you want to eliminate some of these smaller kits with with too little overlap, then you can change that number. So for instance, I want to change this from 45,000 up to 90,000. So I want at least 90,000 snips matching to be able to call it a match.

(17:19):
So when I search through there, now as I go down, what I’m gonna find is that in this overlap column, the very last column, it’s either gonna be na, which means it was already done on GEDmatch. So it definitely has more than that. 90,000 or any of these new kits are gonna be above 90,000. You’re not gonna see any of those 50,000 kits or the red kits that we saw earlier. So those are some different tools you can use on jma. In the one to many matching, remember there’s two tools. There’s the basic one that doesn’t really have a lot of the sorting and then there’s the beta version that you can sort through different things. You can actually change the thresholds for what you’re looking for as far as your overall matches. I would recommend that this is the first place you start when you’re getting onto Genesis and start going over your match list and seeing what matches you actually already know and which ones you may have already matched with through one of the other programs like Ancestry Family Treating A 23 and Me because if they’ve uploaded their kit to GEDmatch and you match them on GEDmatch, you should also find that match on those respective websites.

(18:22):
Now if you have any questions on how to use the one to many tools, put it in the comments below and I’ll try to answer it for you. And if you like this video, be sure to give it a thumbs up and tell your friends.