Some gyms have open mats, usually on a weekends, and the people who go to these gyms are considered to be quite fortunate. This is because this affords the opportunity for people to train with much fewer restrictions than the weekly classes and try out new things that they learnt. Tragically, however, a lot of people waste this chance either by opting to do something else or wasting that time doing the wrong thing
What is this wrong thing? Well, usually, this means just getting on the mats and rolling or sparring with no aim other than to beat their opponent. In other words, it's an exercise in ego boosting rather than skill building. And the hours given for open mats is a great way of working on something you didn't have the time to hone during class, preferably with a good training partner who is trying to help you as well.
While beating your "opponent" or tapping him out may feel good, you can be rest assured that he is not likely to help you next time you really need help. But hey, if you don't require assistance - then be my guest but I can imagine you'll be one unpopular hombre at the gym.
Open mats is for growth, in my opinion. And this growth is..and this part is vitally important...mutual growth. It's not how much I can get for myself in these two hours, but how much I can help my training partner improve and how much he can do for me in this time. This is thus less about a clash of egos than looking out for each other in a nobler way. Another important aspect of open mats is balance out the work/play ratio. It should be fun, but not to the extent that you're sitting, gabbing away on the sidelines after one 2 minute roll. Yes, I've done this before...
One has to train seriously, and intent but with a sense of play. The person I am competing with is myself, no one else. If it's a fight you want, take it to the streets or the Octagon; but not to the open mats where the word is "open"; welcoming you in a friendly, mutually beneficial manner.