pixbet futebol baixar

I'm looking at the two alpha examples on pages 82 and 83:

Example 1):

9 handed 12.5% ante;Action 1️⃣ folds to hero in the SB with 72o and an overly tight player in BB. What's the alpha if we 1️⃣ raise 2.5bb from the SB?

They proceed to show alpha as 2/(2+2.625)=0.43.