I'm focusing on triangulation groups and so looking at matching segments that overlap each other. I'm frequently finding the situation where, at a single website, match A's segment is shown as triangulating with match B's segment, and match B's segment is shown as triangulating with match C's segment, but match A is not shown as triangulating with person C.
Sometimes, the explanation is that the overlap between the segments inherited by A and C is too small, below the threshold established by the company to flag people as matches.
But I'm frequently finding intransitivity even when this is not the case. For instance, I just found on MyHeritage the situation:
Person A and Person B have exactly the same start and end position for their segments that match my kit, and these segments are shown as triangulating. Person C has a segment contained within the segment of A and B, and her segment is shown as triangulating with A's but not with B's. In the situation I'm looking at now the longer segments are 14cM and the shorter one contained within them is 12cM.
I can only guess that person A and B actually had a few differences that were ignored, person B and person C also had a few differences that were ignored, but person A and person C had the union of these differences and put together there were too many for them to be called a match. Is that what I should assume is happening here? Can I put these people all in the same triangulation group, or should I be hesitant?