GEDMatch Confused about my GEDmatch results differing from Myheritage?

[Silah]

Hello dear forum members. Since long time I was curious to find out where my DNA and therefore my ancestors really came from. I ordered a DNA test from Myheritage which told me the following results:
51.7% East European
- 0% Balkan
- 0%Baltic
(So I guess Slavic)
42.4% North and West European
3.2% Ashkenazi Jewish
2.7% Italian
Then I uploaded my raw data to GEDmatch with the Eurogenes K13 model and my admixture results there were:
North_Atlantic -- 38.82
Baltic -- 31.49
West_Med -- 13.12
West_Asian -- 6.47
East_Med -- 6.69
Red_Sea -- 1.02
Siberian -- 0.68
Amerindian -- 1.53
Northeast_African -- 0.18
Now my question how come those results are so different from the Myheritage DNA estimates? For example in Myheritage as mentioned above I had 0% Baltic while in GEDmatch suddenly I'm having 31% !!
Please someone explain me how that is possible and which results are more reliable... I'm really confused right now!

 

[yonaga]

Different definitions/algorithms.

 

[Viberg]

I've tested my autosomal DNA with FTDNA, 23andMe, Ancestry, and MyHeritage. There are wide variations with the ethnicity estimates between the 4 DNA sites. My sister has also tested with the same sites and her results vary wildly. And, me and my sister's ethnicity comparisons show that the proportions of each of our similar ethnic groups is not very close.

I think that the ethnicity predictions are fun to look at, but not very reliable at this point in time. I think that your known family tree that is backed up by autosomal DNA matches that intersect with your family tree is a more reliable basis of learning about your family origins.