He believes there is a risk the sport could lose some of its attraction if this year's campaign fails to form a narrative following its unpredictable start.
"For F1, we must make sure that the random factor is not too strong," Brawn told AUTOSPORT, talking about his reflections on the first half of a year when F1 delivered seven different winners in the first seven races for the first time in its history.
"I think there have been some random elements of this year that have been exciting, but I actually think that [the excitement] will fade after a while if it stays too random.
"There is a funny analogy to fishing, which I was thinking about the other day. In fishing, the great thing is that a complete beginner can come along and catch a huge fish, because there is a randomness to it. That is what makes it really fun for participants - but that doesn't make it a very good spectator sport.
"What we cannot have in motorsport is a randomness where you don't know who is going to win, and that you could work really hard to improve the car but your car doesn't suit the conditions and you are not competitive. That is not where we want to be."
F1 faced criticism from some quarters that it was too unpredictable at the start of the year. Detractors suggested that the huge variations in performance of teams from race-to-race, due to the lack of understanding of Pirelli's 2012 tyres, was a turn-off for hardcore fans.
But Brawn is optimistic that now teams have got a better knowledge of the tyres, the situation is calming down - and he thinks that is vital for F1's credibility going forward.
"To some degree things do appear to be getting better, but the differentials you are getting in teams with their two drivers are still curious. One weekend with Red Bull you have Mark [Webber] almost dominating, and the next weekend it is Sebastian - and no one really understands that.
"There is a pattern emerging, and a trend emerging, as we all get more competent with the tyres. I suspect that is what will happen and, as long as it does happen, that is fine. But what we don't want is the randomness."
He added: "I think there has to be a pattern. There has to be a team or two that are the reference point, and others are trying to beat them and aspire to beat them.
"You need that order for people to enjoy the season, and enjoy the whole year - otherwise there is a randomness and someone who gets it slightly better than someone else might have accumulated more points.
"We want to see guys racing each other. We want to see the guys who are first and second in the world championship being out in front racing each other hard, not one in the midfield and one running away with it because that weekend they got the tyres right."