You might want to check out page 24 of the white paper...

> Mining Pool Resistant
Miners have a total of 3 seconds to receive a block, solve the proof of work, and get the transaction to the next block producer. Much of this time will consist of network latency which means that it is critical for miners to be well connected to the network to make the most effective use of their computational resources.

> Because of the constantly changing head block and network latency, forwarding a template for mining a specific block to participants of a mining pool adds additional network latency and reduces efficiency of pooled mining significantly.