Winning in tough holdem games by stoxtrader

[Rackad]

Im reading Winning in tough holdem games by stoxtrader and on page 102-124 theres countless of results from defending in the big blind. Theyve lost money with all but the best hands so my question is, should u really defend with anything but the best hands here?

Or maybe even if u loose say 0,3BB with A5s in the ling run u should call because of the money thats in the pot allready. As u can tell I dont think ive quite understood these results and how to interpret them correctly.