I want to compare different BU opening sizing (with about 51% RFI) to the corresponding BB defense Frequencies. These are just estimations and i cant go into exact detail because there are too many unknowns.

With 80% EQ realization:
BU opens 2,0bb -> BB needs 28% Realized Equity -> BB defends 100%
BU opens 2,5bb -> BB needs 34% Realized Equity -> BB defends 84,6%
BU opens 3,0bb -> BB needs 39% Realized Equity -> BB defends 57,5%

With 75% EQ realization:
BU opens 2,0bb -> BB needs 30% Realized Equity -> BB defends 100%
BU opens 2,5bb -> BB needs 36% Realized Equity -> BB defends 73,1%
BU opens 3,0bb -> BB needs 41% Realized Equity -> BB defends 49,3%

With 70% EQ realization:
BU opens 2,0bb -> BB needs 32% Realized Equity -> BB defends 93,6%
BU opens 2,5bb -> BB needs 39% Realized Equity -> BB defends 57,5%
BU opens 3,0bb -> BB needs 44% Realized Equity -> BB defends 38,5%

With 65% EQ realization:
BU opens 2,0bb -> BB needs 34% Realized Equity -> BB defends 84,6%
BU opens 2,5bb -> BB needs 42% Realized Equity -> BB defends 43,9%
BU opens 3,0bb -> BB needs 47% Realized Equity -> BB defends 30,6%

1. We know that the shallower the stacks the higher the equity realization should be
2. We know that if we are in position we generally have higher equity realization

Im now wondering why anyone would open more than 2bb from bu vs regs? Arent you just inflating the pot and thus increasing BB's equity realization? Also arent you getting the highest fold equity relative to you opening size the smaller you open because BB has a harder time realizing his EQ the smaller you open?

Im not even talking about you having to open less from the BU if you open bigger.