Back up buddy: There are many ways to get hurt in combat sports but one of the most unnecessary comes in situations where two are sparring in a crowded room and crash into another couple of athletes sparring next to them. This kind of incident is usually dismissed as part of the game and laughed . I never took this approach. In the heyday of the blue basement when was getting ready for a big MMA show or the squad was getting ready for ADCC we would often have well over a hundred people working out in a class. In this type of situation it is absolutely crucial that everyone in the room have a good sense of where they are on the mat relative to the people around them. Nothing is more frustrating than an athlete getting ready for a show and getting injured with a cut from a or a joint injury from someone rolling into their or leg at an inopportune time – I have myself been knocked out cold twice from heel kicks to the back of the head while sparring next to athletes whose enthusiasm exceeded their sense of distancing. When you start getting close to other people – make a point of quickly and fluidly rolling away from them and start where you off. Keep a sense of your surroundings. I teach this in terms of self defense – just as can be a very thing in self defense scenarios, so too it can be dangerous in a crowded training room. Train yourself to pay attention as you grapple in training and it will help you pay attention to your surroundings if you have to defend yourself outside the dojo. There are more than enough ways in Jiu jitsu to get injured without adding this easily avoided method to the list. Students – be the one who keeps awareness of your surroundings and does not injure or annoy those around you. Teachers – run a tight ship. Make students aware of the potential of collision and build a culture in your dojo that takes pride in being professional and courteous and I promise you your injury rate will drop and class camaraderie will increase.