Ancestry Only Shows Shared Matches of 20 cM and Greater – What That Means & Why It Matters

Just lately, I’ve seen an uptick in confused individuals who’ve taken Ancestry’s DNA check.

They’re utilizing shared matches, which is a superb instrument and precisely what they need to be doing, however they turn out to be confused when no shared matches seem with some particular folks.

That is particularly perplexing once they know by means of info sharing or as a result of they handle a number of DNA kits that these two individuals who each match them really do share DNA and match one another, that means they “ought to” seem on a shared match record. Or worse, but, conflicting match info is displayed, with one particular person displaying the shared match, however the different particular person reciprocally doesn’t.

What provides?

That’s precisely what this text addresses. It’s not fairly so simple as it sounds, but it surely’s definitely simpler when you perceive.

What Are Matches and Shared Matches?

Matches happen when two folks match one another. Out of your perspective as a DNA tester, matches are individuals who have taken DNA checks and seem in your match record since you share some degree of DNA equal to or higher than the match threshold of the seller in query.

At Ancestry, that minimal matching threshold is 8 cM (centimorgans) of matching DNA.

Particular person matches are all the time one-to-one. Your match record is an inventory of people that all match you.

So, you match particular person 1, and also you match particular person 2, individually.

Your matches might or might not additionally match one another. In the event that they do match one another along with matching you, that’s a shared match which is a trace as to a potential frequent ancestor between all three folks.

Shared matches are an inventory of people that match you PLUS anyone different match in your record. In different phrases, shared matches are three-way matches.

Within the diagram above, you possibly can see that you just match Match 1 and also you additionally match Match 2. On this case, Match 1 and Match 2 additionally match one another, so all three of you match one another, however not essentially on the identical phase. Subsequently, you’re all three shared matches, as proven within the middle of the three circles.

Viewing Shared Matches

To view an inventory of people that match you and Match 1, you’d request shared matches with Match 1 by clicking on “View Match” or “Study Extra” in your match record, then on “Shared Matches” on the following display.

The ensuing shared match record consist of people that match you AND Match 1, each. It’s simple to make assumptions about why you’ve got shared matches, however don’t.

Shared Matches are Hints

A shared match CAN imply:

  • That every one three folks share a typical ancestral line.
  • You share a typical ancestor with Match 1 and Match 2, however Match 1 and a pair of match one another as a result of they share a wholly totally different ancestor.
  • You match Match 1 since you share DNA from Ancestor A and also you match Match 2 since you share DNA from Ancestor B. Match 1 and a pair of match one another both as a result of they share one or each of these frequent ancestors.
  • Match 1 and Match 2 would possibly match as a result of Match 1 and Match 2 share an ancestor that isn’t associated to you.
  • That one (or extra) of the matches is identical by chance, that means the DNA mixed from two mother and father in a random means that simply occurs to match with another person.

Shared matches are nice hints to be sifted for relevance. The operative phrase right here is trace.

What If We Don’t Have Shared Matches?

Conversely, NOT having a shared match doesn’t imply you don’t share a typical ancestor.

Sorry concerning the triple detrimental. Let me say that one other means, as a result of that is necessary.

Despite the fact that you and another person aren’t on a shared match record, you would possibly nonetheless share DNA and chances are you’ll share a typical ancestor, whether or not you share their DNA or not.

Ancestry’s shared matches work in a different way than shared matches at different distributors. Earlier than we talk about that, let’s speak about why shared matches are necessary.

Why Do Shared Matches Matter Anyway?

Matches and shared matches are how genealogists carry out two critically necessary capabilities:

  • Verifying “identified” ancestors. Typically paper trails aren’t correct and positively, neither are timber.
  • Figuring out unknown ancestors. Searching for frequent households amongst shared DNA matches is a HUGE trace when monitoring down these pesky unknown ancestors.

I wrote about shared matches, here, when Ancestry purged segments underneath 8 cM, however I believe the message concerning the limitations of shared matches and the way the method really works deserves its personal article, particularly for brand spanking new customers. Shared matches and phase cM numbers could be fairly complicated, however they don’t have to be.

I wrote an article titled DNA Beginnings: Matching at Ancestry and What It Means that features numerous helpful info.

Okay, now let’s look particularly at utilizing shared matches and why generally shared matches simply don’t appear to make sense.


By far, the vast majority of your matches at any vendor shall be extra distant matches. That’s as a result of you’ve got 1000’s of distant family, most of whom you don’t know (but).

You’ll solely have just a few nearer family.

At Ancestry, I’ve 102,000+ complete matches, of which greater than 97,000 are distant matches. Primarily based on these numbers, take into account that about 95.74% of my matches are distant, that means 20 cM or beneath, and yours in all probability are too. You’ll want that quantity later.

Be aware that 20 cM is Ancestry’s threshold between shut matches and distant matches.

That’s about precisely the place you’d count on, on common, to see a 20 cM match – usually at or additional again than 4th cousins. 20 cM is roughly the 4th to sixth cousin degree.

After all, you received’t match most of your 5th cousins in any respect, but you’ll match some with greater than 20 cM. That’s simply the roll of the genetic cube.

Nearer ancestors (that means nearer matches) can be the realm of family tree the place a lot of the lower-hanging fruit has been plucked.

In my case, the closest unknown ancestor in my tree happens on the 6th technology degree and I’ve 5 or 6 lacking sixth-generation ancestors – all females with no surnames. Two don’t have any names in any respect.

Click on to enlarge any picture

How A lot DNA Do Cousins Share?

One in all my priorities as a genealogist is to determine these unknown folks, which is why matches, and shared matching at that degree are vital for me.

Ancestry tells me that this 20 cM match is probably going my 4th-6th cousin.

At DNAPainter, within the Shared cM Tool, you possibly can enter the full cM variety of a match, which is the full quantity of DNA that you just share after Ancestry’s Timber algorithm has been applied. The vary of relationship possibilities for 20 cM is proven beneath.

For a complete match of 20 cM with one other particular person, a number of relationships ranging between half 3C2R/3C3R and eightth cousins are probably the most possible relationships at 58%.

For the report, that is complete cM, which doesn’t essentially imply one phase. Ancestry reviews the variety of segments, however Ancestry doesn’t present you the phase places, nor have they got a chromosome browser. With no chromosome browser, you don’t have any means of figuring out whether or not or not you match with shared matches on the identical phase(s). In different phrases, there is no such thing as a triangulation at Ancestry, that means affirmation of a particular shared DNA phase descended from a typical ancestor. Yow will discover triangulation resources, here.

Shut Matches

The easiest way to determine how you might be associated to nearer matches (assuming you don’t already know them and Ancestry has not discovered a typical ancestor) is utilizing shared matches. Hopefully, you’ll share matches with folks you do know or with whom you’ve already recognized your frequent ancestor.

One in all my comparatively shut DNA matches at Ancestry is Lonnie. I don’t know Lonnie, but it surely appears like I ought to as a result of he’s in all probability a 1st or 2nd cousin. We share 357 cM of DNA over 20 segments.

I believed I knew all of my 1st and a pair ofnd cousins. Let’s see if I can work out how I’m associated to Lonnie.

By clicking on Lonnie’s title on my match record, then on Shared Matches, I can decide that Lonnie and I join by means of my Estes and Vannoy traces primarily based on who we each match, which signifies that our frequent ancestor is both my paternal grandfather or my great-grandparents, Lazarus Estes and Elizabeth Vannoy.

You possibly can see the notes I’ve made about these matches I share with Lonnie.

Viewing Lonnie’s unlinked tree verifies the ancestral line that shared matches recommend. An unlinked tree signifies that Lonnie has not linked his DNA check to himself in his tree. Since Ancestry doesn’t know who he’s within the tree, they will’t discover a frequent ancestor for me and Lonnie. Nonetheless, I can by viewing his tree.

Our frequent ancestor is Lazarus Estes and his spouse, Elizabeth Vannoy. Subsequently, Lonnie is my 2nd cousin.

That wasn’t troublesome, partially as a result of I had already labored on the family tree of our frequent matches and Lonnie had a small unlinked tree the place I may affirm our frequent ancestor.

Now let’s transfer to extra distant, not-so-easy matches.

Distant Matches

I’ve spent quite a lot of time over time figuring out frequent ancestors with my matches.

Once I make that connection, whether or not or not Ancestry has been capable of determine our frequent ancestor, I make notes about frequent ancestors and anything that appears related. Notes very conveniently present on my match record so I don’t have to open every match to see how we’re associated.

Ancestry does determine potential frequent ancestors utilizing ThruLines. Be aware the phrase potential. Ancestry compares the timber of you and your matches looking for frequent ancestors and suggests connections. It’s as much as you to confirm. ThruLines are hints, not gospel. Moreover, you could have a number of ancestral hyperlinks to your matches. Ancestry can solely work with the truth that you’ve got a DNA match with somebody AND the user-provided timber of your matches.

Ancestry’s ThruLines solely attain again a most of seven generations to recommend frequent ancestors. At 7 generations distance, you’d be a 5th cousin to a descendant who can be 7 generations downstream from that ancestor.

The data from DNAPainter, who makes use of the Shared CM Project compiled knowledge reveals that the more than likely quantity of shared DNA for fiveth cousins, is, you’ve guessed it – 20 cM.

Jacob Dobkins is my 7th technology ancestor. I’ve ThruLines for him and his spouse, however not for his or her mother and father who’re one technology too distant for ThruLines. I’d LOVE to see Ancestry lengthen ThruLines one other 2 or 3 generations.

ThruLines matches me with individuals who descend from Jacob by means of his different youngsters. Different youngsters are necessary as a result of the one ancestors you share with these persons are (presumably) that ancestral couple.

Matches with Jacob’s descendants vary from 8 cM (the smallest quantity Ancestry reviews) to 32 cM.

Right here’s an instance.

Ancestry shows some shared matches with your whole matches, whatever the measurement of your match to that particular person. Nonetheless, Ancestry ONLY reveals shared matches to a 3rd particular person should you share greater than 20 cM of DNA with that third particular person.

For instance, I match KO with 8 cM of DNA. Ancestry reveals my shared matches with KO, beneath.

I solely have 3 shared matches with KO. I solely match KO at 8 cM, however I match our shared matches at 39, 31 and 21 cM, respectively.

Ancestry does NOT present shared matches beneath 20 cM, so it’s unknown what number of further shared matches KO and I even have if shared matches lower than 20 cM have been displayed.

Perspective is Vital

Whether or not you see a shared match or not is typically a matter of perspective, that means which of two folks you request shared matches with.

On this case, I requested shared matches with KO. I solely share 8 cM of DNA with KO, however that doesn’t matter. The quantity of DNA you share with the particular person you’re requesting shared matches with is irrelevant.

Ancestry’s Shared Matches with KO embrace Ker

I’ll see shared matches with KO to anybody we mutually share as matches above 20 cM, together with Ker.

If I request shared matches with Ker, with whom I share 39 cM of DNA, I’ll see all of our mutual matches at 20 cM (or higher) of DNA. Nonetheless, that does NOT embrace KO as a result of I solely share 8 cM of DNA with KO.

This restriction applies no matter how a lot DNA KO and Ker share, which is an unknown to me in fact.

Ancestry’s Shared Matches with Ker does NOT embrace KO

Nothing has modified between these matches, but KO doesn’t seem on my shared matches record with Ker once I request shared matches with Ker.

I nonetheless share 8 cM with KO and 39 cM with Ker. KO and Ker nonetheless each match one another. The one distinction is that Ker reveals up on my shared match record with KO as a result of I share greater than 20 cM with Ker. Nonetheless, once I request a match record with Ker, KO does NOT seem as a result of I solely share 8 cM with KO.

That is the supply of the confusion and infrequently, why folks disagree about shared matches. It’s type of a “now you see it, now you don’t” scenario.

If an individual reveals as a shared match will depend on:

  1. Whether or not the third particular person really does share DNA with the tester and the particular person they’ve requested for shared matches with
  2. Whether or not the third particular person shares 20 cM DNA or extra with the tester, the particular person requesting the shared match record with one among their matches

Whether or not somebody seems on a shared match record can actually be a matter of perspective except the match and the shared matches all match the tester at 20 cM or bigger.

One other Instance

Let’s take a look at a bigger match to a descendant of the identical ancestor.

I share precisely 20 cM with Joyce, my 6C1R.

Viewing my shared matches with Joyce, I match 50 different those that she matches as properly.

I solely share 25 cM of DNA with the smallest match with Joyce. Apparently, there are not any matches with Joyce with whom I share between 20 and 25 cM of DNA.

Backside Line

Right here’s the underside line.

Ancestry NEVER reveals any shared matches beneath 20 cM from the attitude of the tester, that means individuals who match you and another person, each.

If you happen to recall our earlier math, that signifies that roughly 95.74% of my shared matches aren’t proven.

This places shared matches in a special perspective as a result of now I understand simply what number of matches I’m not seeing.

Why is This Complicated?

If you happen to aren’t conscious of this shared match limitation, and {that a} majority of your shared matches are literally beneath 20 cM, chances are you’ll interpret shared match outcomes to imply you really DON’T share particular matches with that different particular person. That isn’t essentially true, as we noticed above with KO and Ker.

Moreover, let’s say you handle your DNA equipment plus 3 extra, A, B and C. Since you handle all 4 kits, which means you possibly can see the outcomes for all 4 folks.

  • A – 10 cM
  • B – 20 cM
  • C – 40 cM

From the attitude of YOUR equipment, you will notice some shared matches FOR all of these matches.

What you received’t see is shared matches should you don’t match the shared match (third particular person) at 20 cM or higher.

At all times keep in mind, shared match info at Ancestry is ALWAYS from the attitude of your DNA equipment mixed with the particular person with whom you request the match.

I’ve put this info in a grid as a result of that’s how I make sense of issues like this.

Listed below are your matches. While you click on on shared matches with particular person A who you match at 10 cM, you’ll see each particular person B and particular person C as shared matches because you match each of these folks at 20 cM or bigger. You WILL see 20 cM shared matches, however you’ll not see 19 cM shared matches.

While you request shared matches for A, you will notice each B and C.

While you request shared matches with kits B and C, you’ll not see A since you solely match them at 10 cM.

Nonetheless, from the attitude of DNA kits A, B and C, shared matches look totally different.

Let’s take a look at shared matches from the attitude of Kits A, B and C.

Package A matches you, Package B and C, however can solely see Package B as a shared match as a result of matches with you and Package C are underneath 20 cM.

Package B doesn’t match C in any respect, in order that they clearly received’t have shared matches. Nonetheless, they do match you and Package A, each at 20 cM and over, so Package B will see you as a shared match with Package A, and Package A as a shared match with you.

Package C doesn’t match Package B, so no shared matches with that particular person in any respect. Package C does match you and Package A. Nonetheless, when Package C clicks on shared matches for you, Package A doesn’t present up as a result of they solely match Package A on 9 cM. When Package C clicks on Package A for shared matches, you ARE listed as a shared match since you share 40 cM of DNA with Package C.

There’s no approach to discern whether or not two of your matches match one another except they present as a match within the shared match instrument. You possibly can’t inform if their absence on the shared match record means they really don’t match, or their shared match absence is as a result of they match you at lower than 20 cM.

Whew, that was a mouthful.

It’s possible you’ll have to refer again to this every so often should you’re confused by your shared matches at Ancestry.

If you have to keep in mind guidelines, keep in mind this.

  1. You possibly can acquire shared matches with your self plus any match, no matter how a lot or how little DNA you share with that one match. Show this to your self by discovering a match underneath 20 cM, like my 8 cM match, and viewing your shared matches.
  2. Nobody will present on a shared match record with one other particular person except they match you at 20 cM or higher. Show this to your self by viewing the smallest shared match with anybody.


The takeaway of that is you probably have a bigger (20 cM or over) and smaller match (underneath 20 cM), all the time request shared matches from the attitude of the smaller match as a result of the smaller match received’t present up as a shared match on any shared match record.

The one means you possibly can see shared matches that features folks underneath 20 cM is to request to view shared matches with particular person individuals who match you beneath 20 cM. 

In my case, I’ll by no means see KO on any shared match record as a result of I solely match KO at 8 cM. Nonetheless, I can request my shared matches with KO during which case I’ll see all 20 cM or higher shared matches with KO.


Each vendor gives a shared match function, and every capabilities in a different way.

Within the chart beneath, I’ve supplied primary shared match info for every vendor.

If you happen to’re taken with importing your DNA file from Ancestry or one other vendor, I’ve supplied add/obtain step-by-step directions for every vendor, here.


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