Here's my attempt at making the terms of my bet with RHavar unambiguous:

1. A "network upgrade event" is defined to have occurred if the blockchain (or one side of the blockchain should a split occur) contains a block larger than 1 MB and at least 72 blocks have been built on top of it.  These blocks must be built using the current PoW algorithm and with no reset or fork-based reduction in the difficulty.

2. Conditions where RHavar wins the bet:

   - A "network upgrade event" occurs, resulting in a blockchain split, and at least 2100 blocks are built on the "small block" side of the split (i.e, the blockchain branch that contains no blocks larger than 1 MB) within 4 months (120 days) of the splitting point.  The blocks must be built using the current PoW algorithm and with no reset or fork-based reduction in the difficulty.
  
3.  Conditions where Peter R wins the bet:

   - A "network upgrade event" occurs and the blockchain contains at least one block larger than 1 MB and no blockchain split occurs.
   - A "network upgrade event" occurs and the blockchain contains at least one block larger than 1 MB and 2100 full-difficulty regular-PoW blocks are not built on the small-block chain within the 120 day window.
   - Should the minority chain become unusable for whatever reason prior to reaching 2100 regular-PoW/full-difficulty blocks, thereby requiring a change in PoW or a reset or reduction in difficulty in order to keep it alive, then Peter R wins the bet provided the big-block side of the blockchain contains a block larger than 1 MB.    

4. Conditions for a draw (Peter R and RHavar receive their wagers back)

   - No "network upgrade event" occurs between now and 31 December 2017.