partners with Twitch: a play for focal and membership closure

The livestreaming giant Twitch and the widely used chess website, recently partnered. This means that we will likely see many chess fans that would not otherwise watch streams on Twitch, using the platform. Bringing in this new audience, that isn’t necessarily interested in other games on Twitch in the first place, to socialize in the chat functions on Twitch will likely make some of the chess audience watch other streams on twitch as well.


The underlying reasons for this can be explained through the principal of focal and membership closure. The definition of focal closure is, according to Networks, crowds and markets (David Easley and Jon Kleinberg 2010): “If B and C represent people, but A represents a focus, then this is something different: it is the tendency of two people to form a link when they have a focus in common. This is an aspect of the more general principle of selection, forming links to others who share characteristics with you”. According to same book, the definition of  membership closure is: “If A and B are people, and C is a focus, then we have the formation of a new affiliation: B takes part in a focus that her friend A is already involved in. This is a kind of social influence, in which B’s behavior comes into closer alignment with that of her friend A”. To summarize, we can say that focal closure is when two people with a common focus become friends, and membership closure is when a person adopts a focus of his/her friend.


How does this relate to focal and membership closure? Imagine the chess stream as node A (the focus), the person that is originally only interested in chess as node B, and a person who is interested in chess as well as game X, as node C. We then have edges AB and AC, and the edge BC is likely to form due to focal closure. Should the edge form, we will have an opportunity for membership closure between B and game X, since we have BC, CX, but not BX.

This can be viewed as “Tom and Bob became aquainted in a stream. Bob asks Tom if he has been following the latest Hearthstone tournament. Tom says no, but trusting Bob’s judgement, he decides to check it out”. Thus, bringing in this new audience will likely get people that were previously not interested in any other games on Twitch than chess, to check out other games.



David Easley and Jon Kleinberg. 2010. Networks, Crowds and Markets.
Cambridge University Press.