Let me reach way back to my first RPG theory; gaming is about sharing. Since it is about sharing 'new stuff', it takes a certain amount of preparation. Typically, everyone did a little, but the gamemaster did much more. It follows that he has the most to share. The players are pretty up-front about their 'new stuff' allowing each other see it right away. The gamemaster keeps his close to the vest, creating a sense of anticipation using the 'unknown'.
In typical gaming, the social circumstance determines the expectation of linearity; that is following a plot, a predetermined series of events, a cycle of escalation, and the like. Misunderstandings from the extremes of this always cause problems. Generally speaking, things move from one event to another in verisimilar order.
Spotlight time has always been handled on the social level in typical games. I mean, sure some games talk about chara abilities as the manner of commandeering the spotlight, but by and large, they are treated as more a veto power over unstructured play. Spotlight control is then mostly left to the gamemaster. Many typical games feature discussions about administering it fairly and appropriately.
Ultimately this includes other social responsibilities such as pacing control, maintaining a sense of fairness, establishing a 'tone' for the game as well as many others. Instructions have been scant on how to handle these things, but there has been a swell fairly recently.
Next time, let's tackle what people want out of their gaming.