Every feed is late to someone.
Twelve feeds quote ETH/USD. On the last 40 bps move, 2.8 seconds separated the first update from the last. Whoever sees the first kink sees the price before most of the market does.
The field drifts. One feed leads.
Each feed hangs in the field as a constellation. Before every move its ephemeris is public: the last five updates, stated to the millisecond. Read them. Lock the reticle on the feed you expect to move first. Observe. If it leads, a halo stays at that feed and timestamp.
Enter the map