I was at a bris this morning, and I heard something interesting. One of the chashuvei mishpachas Brisk told me that Reb Chaim Brisker and the Rogotchover learned bechavrusa as boys (Reb Chaim was five years older.) Let that sink in.
(I just saw that this was mentioned on Wiki, which doesn't mention they learned bechavrusa, but does say that they learned by Reb Chaim's father, the Beis HaLevi, in Slutzk.)
Another story- there was a din Torah, and one side chose the Rogotchover, and the other Reb Chaim. They wanted Reb Chaim Ozer to be the third, but Reb Chaim Ozer didn't want to do it. He was afraid the Rogotchover would attack him ceaselessly and make the job impossible. Reb Chaim told him that what he should do is when the Rogotchover starts throwing marei mekomos at him, he should throw marei mekomos back- from random sugyos that are marginally related to the discussion. From Sifra, Yerushalmi, Pirkei D'Rebbi Eliezer, Moreh Nevuchim, anything. Figuring out what the marei mekomos were supposed to prove would distract the Rogochover long enough for them to get their business done.