Tinguinha is a BJJ black belt who is known for his open guard work, especially his Spider Guard, recently shared a video where he shows a technique in the academy, and offers a clip from him fighting in competition nailing the same move. Pretty slick IMO.
I have also put a few quotes from an interview that can be found on Tinguinha's website. Here is some insightful philosophies and approaches to BJJ from BJJ black belt Helio Soneca. I missed an opportunity to train with Soneca a couple years ago and I am still regretting it.