Yeah I hear that.
Beanie Sigel said in an interview. Jay saw him writing his verse in a studio and threw away his notebook and said he should do it in his head lol.
I call suspect on more of the intricate rhymes Jay and Big tend to do, that's hard to pull off coming without pen and paper to see your rhyme pattern, subject on point, and etc. Also not Jay but Biggie has been caught using pen and paper. RA the Rugged Man told DJ Vlad Biggie used a pen and pad when writing his verse for their record.
Biggie always went home to use a pen and paper in my opinion because he has never recorded a verse in any collaboration while the other artists were there. He always went home. The Lox, BTNH, Brooklyns Finest, etc, Biggie always went home first then came back to record by then you could memorize anything. I give Jay more credit for coming off the top when writing with no pen or paper. Biggie is far more suspect lol.
But hey they are both mega skilled at rapping however their formula lol, the new generation need to at least master the art of writing though.