How I synced real-time CS2 predictions with Twitch stream delay

I am building elo.market , a real-time prediction system for CS2 streams. At first, this sounded simple: the game emits events, I create predictions, viewers vote. Then I ran into the actual problem: my backend knew about round starts, bomb plants, and round ends before Twitch viewers saw them. So this stopped being a "realtime UI" problem and turned into a timeline problem. The hard part was not generating predictions. The hard part was preserving a believable timeline for each viewer. Because on Twitch, there is no single "the stream is delayed by X seconds" value. There are at least two different delays involved: the broadcaster's intentional stream delay each viewer's personal playback delay caused by Twitch buffering, network conditions, device behavior, and low-latency mode If you get this wrong, the whole product feels broken: predictions open too early and spoil what is about to happen predictions close before the viewer even sees the moment odds update before the actual predic