When a miner finds a valid block, they want to broadcast it ASAP to the entire network—this is competitive block propagation. If other miners receive it quickly, they’ll switch to building on that block, reducing orphan risk. Techniques like Compact Blocks and other relay optimizations help new blocks spread within seconds.

Speed matters because any delay in sharing a newly discovered block means other miners might also discover a block on the old chain, creating a short-lived fork. The miner whose block is more widely recognized first often wins, while late-propagating blocks can become orphans, denying that miner the block reward. Hence, efficient propagation infrastructure is critical for competitive mining operations.