What do directors seek to establish in the opening of thrillers? (unfinished)

With every opening of a film it has to be able to make the viewers interested and into the movie straight away, so then the rest of the movie gets good expectation from the audience. A 'interesting' opening comes from make the audience intrigued to see the rest of the movie, directors use certain techniques to do this such as introducing some of the characters and maybe even show key parts of what the story is about. Another great way is to make the opening have a voice-over which can then talk about about the characters story which works well because if the shots aren't that interesting the voice-over does keep you on track. With some openings all it takes is to thrill the audience, to do this directors use maybe chase scenes or actions scenes etc.

An example of an interesting and thrilling opening would be from Lock, Stock, and Two Smoking Barrels. The film starts off with Bacon (Jason Statham) illegally sell products on the side of a street, which leads to the police noticing and chasing him which has already created a sense of excitement to the audience. The chase is also well shot as it uses a handheld shaky cam affect as he runs towards and past the camera.

The next shot is very creative and unique as it parts of the shot are in slow-motion, for example the second man Eddy (Nick Moran), comes into shot fast from around the corner and hits the wall in slow-motion. These kinds of edit are very well done and give the shot a lot more variety which makes it more exciting. Another part of the scene that uses slow-motion is the part as Bacon throws the suitcase of items towards Eddy which leads to the suitcase opening and the items go flying. Again the use of slow-motion in this scene is great as if it wasn't in slow motion it would of looked a bit chaotic, where as now it looks cool. The slow-motion also works amazing with the music in the background (Ocean Colour Scene - Hundred Mile High City) because of how fast and exciting it is.