Annotation Vertical Alignment

[CandiceLI]

Hi everyone, 

I would have some process on geodatabase annotation feature class based on annotation alignment. Changing the alignment attributes of features is not a good option for my case.  Does anybody know how ArcGIS set the 'Bottom' alignment comparing with 'Baseline' alignment? 

By my guess, it looks like 20% of text height lower than the baseline.

Any guide or suggestion would be greatly appreciated!

Regards,

Candice