It's based on EPV, another horse dung stat championed by the worldwide leader in sports horse dung and the article is from the leaders in abusing horse dung stats. Now there's a helluva combo...if you're making fertilizer
I don't advocate doing it as a primary means to move the chains. I advocate playing conservatively and mixing it in unpredictably. It primarily works because it is unpredictable, IMO. Nothing scientific about my opinion though.