First Touch Attribution - Sum of credits does not make sense

[HumlDavid]

Hello professionals,
I would like to get suggestion from others what could be the root cause

Scenario:

We use First Touch attribution, in implicit model. In Program Opportunity Analyser I isolated a single opportunity as an example - see attached. Opportunity has 1 contact role (should not be relevant) and linked account has 60+contacts.

I can see many programs have been linked to the opportunity, but when I sum the credits it just does not adds up.

• How is it possible sum is 6? Shouldn't single opportunity credits always adds up to to 1?
• Why some rows are included, even though their attribution is 0? Is it because those are from contacts in the account that were maybe acquired AFTER that opportunity was created?
• If there are 60 contacts, shouldn't one credit be 1/60 = 0.017. Therefore I find associated 1.77 and 0.47 very suspicious

Any advice?

Am I misinterpreting the First Touch results? Or is it a bug?