I think most everyone involved in grappling has probably heard the axiom, Position before Submission, suggesting that you pretty much have to achieve a stable, dominant position before you can have much success with a submission. But have you ever thought about it this way - Position leads to Choke leads to Armbar.
Think about it - you get a dominant position and attack the guy's neck and he begins resisting and struggling, trying to negate the choke. In this situation not only does the choke distract him from the armbar, but he tends to push or pull his arms into awkward positions. Thus position-choke-armbar is a general recipe as to how grappling encounters seem to go.
Perhaps the most fundamental example of this recipe might be the following: achieve tateshiho (the mount) and attack jujijime (cross choke). From here uke begins picking and pulling at your hands to counter the choke and you turn 90 degrees and lay back into jujigatame (the cross armbar). Following is a video in which they are not attacking the neck explicitly but you can see where the choke fits into this sequence.
Can you give me 1-2 more combinations that seem to fit this profile - position then choke then armbar?