The only way that you can delete ten best days is when your BAM! cpid is the same as the stats entry where you try to delete them.
I have tried to change the cpid in BAM a while ago and just clicked it again to change it. The BAM cpid is pointing to this project and cpid. https://www.boincstats.com/stats/169/user/detail/2187
I have not been user 169 for a long time over 6 months or even 12 months.
That project does not have that cpid on the project page but has the cpid of all the rest of my projects and that is this one https://www.boincstats.com/stats/-1/user/detail/4350317/overview
This is the xansons for cod screen
Email address firstname.lastname@example.org
XANSONS for COD member since 23 Nov 2016
Change email address · password · other account info
Used in community functions
Account keys View
When and how BOINC uses your computer Computing preferences
Message boards and private messages Community preferences
Preferences for this project XANSONS for COD preferences
Computing and credit
Total credit 1,587,705
Recent average credit 0.09
Computers on this account View
Cross-project statistics BOINC Combined Statistics
The Knights Who Say 'Ni!'
BOINC Statistics for the WORLD!
BOINC all Project Stats
Cross-project ID: f82dc8c0703cb0764e0849345467b89e
Certificate Account · Team
Stats on your cell phone http://xansons4cod.com/xansons4cod/userw.php?id=144