<b>Every community has a bus factor</b>

<b>Every community has a bus factor</b>

Borrowed from software, 'bus factor' asks how many key people you'd have to lose before the project collapses. Communities have one too, and it's usually alarmingly low.

<b>What the data shows</b>
Message-attribution analyses of active servers routinely find that a tiny core — often under 10 people — produces the majority of substantive conversation, even in communities of thousands. When network analysis is applied, conversation frequently routes through a handful of high-centrality hubs. Lose two or three and activity can fall off a cliff.

<b>Why it happens</b>
Conversation is a reciprocal network, not a crowd. A few people initiate the threads everyone else replies to. They're load-bearing in a way headcount completely hides — the org chart of a community lives in who-replies-to-whom, not in the member list.

<b>Discord vs Telegram</b>
Telegram broadcast channels concentrate this to the extreme — bus factor is often one (the operator). Discord groups spread it slightly across active regulars.

<b>The caveat</b>
Centrality measured over short windows overstates fragility; some hubs are replaceable over time as others step up. The network adapts, sometimes.

Open question: can you deliberately lower your bus factor by cultivating second-tier hubs, or does conversational gravity resist being engineered?