One thing readers hate are coincidences. Sure, coincidences occur in our lives every day, but in a story, they are generally a problem. Readers lose interest when coincidence leans in the protagonist's favor because coincidence or convenience does not convey meaning. It is only through conflict that character is revealed. In fact, readers often perceive coincidence as an author's way of cheating.
For example, if Bob is hitchhiking on a deserted road, trying to get to Chicago for a wedding, and he is picked up by Chuck, the best man, who just happens to be passing by -- that is a coincidence. But if Bob is thumbing it to Chicago and just happens to be picked up by the husband of the woman he's having an affair with -- that is synchronicity. Synchronicity conveys meaning, while coincidence does not.
Coincidence lacks conflict. It's expedient, and it's often an indication of where the writer is stuck. Rather than exploring what he or she is attempting to express, the writer simply creates a loophole and proceeds. But just because the author kept writing does not mean that the reader hasn't closed the book. Synchronicity speaks to the underlying meaning of what the writer is attempting to express. There's a reason for the event, which raises the stakes.
If you find yourself relying on coincidence to move your story forward, see if you can find a way to disguise it by creating conflict that is germane to your theme. It doesn't mean that you need to ditch your idea of Chuck giving Bob a ride, but you might want to inquire into why this ride will be more trouble than either character had bargained for. You can keep your story points -- as long as you lose the coincidences.
Alan Watt is the author of the bestselling book on writing, The 90-Day Novel. He has been running the creative writing workshop LA Writers Lab since 2002. Visit him online here.