I don't have too much to say about this film which shouldn't be interpreted as a black mark on the film itself. Truthfully I feel ambiguous about it. Neither dull or exceptional it comes immediately to mind as calculating. It's like walking the circumference of a large abstraction, trying to figure out its purpose.
Tinker Tailor was originally a novel adapted previously for television in 1979 by the BBC. The story is set in the Cold War era of the 70's concerning the investigation of a double agent inside the British Secret Service. You've probably heard about it and if you've seen the trailer then you know it has a stellar cast.
It's the type of story with long pauses and little dialogue which means you sometimes have to explain the subtext to your fellow movie goers. This is the same with the frequent flashbacks. There is a lot to like about Tinker Tailor including some suburb acting.
It felt long and thats the worse thing I can say about it. As I realized I had fifty minutes of runtime left I just thought 'Really?'. 'They can keep this going for another hour?'. And they did. Even at the resolution there was no rushing. Discovering the identity of the trader was over in a moment. There was tension but no action, no fight. This is not Bond after all. It worked though and all the elements of the film make sense.