In our Family Matching algorithm, the number of matching segments you have with a relative is considered more important than the overall length of segments for most of your relatives.
This means that if you have two matches with the same total cM value, but one has two segments and the other only has one, then it is likely that the two-segment match is a closer relative.
The more segments you share the closer you are related, but this is only the case when considering more distant relatives (2nd to 4th cousins). It's not quite the same for Parent/Child and Full Sibling relationships.
. The number of segments is taken into account by our Relationship Distance Estimation method (ERSA).