I'm not even sure how to ask this question so here goes:

The bitcoin mining network is hashing away and pool X finds a block - question:  once a miner sees that a block is solved, how does it know where to start mining the next block?

Example:
- block found
- network notified
- Miner 1 > starts to brute force the next block by trying 1111, 1112, 1113, 1114
- Miner 2 > starts to brute force the new block by trying
- Miner 3 > starts to brute force the new block by trying
- Miner 4 > starts to brute force the new block by trying
- Miner 5 > starts to brute force the new block by trying

What's to keep all 5 miners from starting at the same starting position and therefore (basically) finding the 'solution' at the same time?  Is there some sort of randomization calculator built into the software so the miners all start at a different point??  I mean if I have 5 miners going myself and they are all trying to solve the same problem and they are all starting at the same start position they would all be doing the same work!

I hope this makes sense - sorry for the crude example!