Openings+Ranking

 Assessing the effectiveness of:

 1. The romance openings (based on how they introduce a time, place, keep the reader's attention, introduce/hint at a genre, possibly begin to set the scene for plot development (in this case how it is related to the prompt) and also considering the fluency of writing):

 Opening 3 quickly sets a mood and characters, and proposes a relationship between the latter, as is generally targeted in the romance genre. It achieves this through describing things such as intimacy between the characters (comfort in each other's presence, holding hands; general things lovers do) as well as setting a contented mood via long sentences which repeat certain words (such as "I was outstretched and she was outstretched and"--giving it a certain flow/rhythm). It also hints at the setting--there is grass, there is sun, there are two characters laying on their backs comfortably and waiting for someone. Other onomatopoeia such as "cooed," "hum" and "zip" evoke precise images relating to the setting, and theme and genre.

2. The mystery openings (based on similar aforementioned points):

Though Opening 5 would make a more enjoyable read (in my opinion), opening 6 does a better job of introducing things from the beginning. It starts with two characters talking with each other--this shows characterization (how the characters speak and interact with one another) as well as a relationship between the characters (if they're colleagues, who is their boss? And if they're friends?). Through their conversation, it also sets a scene--Maurice trips on nothing, even though he could have tripped on rocks or logs or even a particularly knotted clump of grass (so they're outdoors) and asks if he could, perhaps, borrow the flashlight (which means it's dark). The other character, B, (perhaps a nickname) begins to become very nervous as they approach a night carnival, snapping at his companion and warning him that he can't mess this up--whatever "this" is. It was supposed to leave the readers with unanswered questions--enough to keep reading to see the situation (in this case, a plot development, whether integral or not) unfold.

3. The sci-fi openings:

 Opening 7 quickly introduces a situation--two characters arguing over the identity of an interesting, undefined object. From their short conversation you can infer a very comfortable relationship between the two, as well as a bit of an idea over what they're arguing about; to one person, it looks like a comet (or maybe a snowman) and to another it looks like a spacecraft. Though the word choice and sentence length (as well as other features of writing) does not hint at the genre, it should be quite obvious that either it's a sci-fi story, or its obvious nature is in mocking irony of the genre.