MESORAS RAV MOSHE

 https://mishpacha.com/mesoras-rav-moshe-rav-michel-shurkin-shares-an-insiders-view/

Another factor at work in every psak from Rav Moshe was his insistence on knowing all of the facts before ruling on a matter. He would quote from the Gra, who derived from two teachings of Chazal that it’s not enough for a rav to know the halachos in Shulchan Aruch clearly; he must also know the pertinent facts.