The reporting system has undergone a major refactoring and so redistribution works somewhat differently now.
Reporting is now essentially a series of increasing stake on assertions that an outcome is correct. The first such staking of REP is the initial report, which is done by the designated reporter or whoever shows up if the designated reporter doesn't show.
Once an initial report is placed reporters may contribute to a dispute of the tentative outcome by asserting a different outcome. If they reach the dispute threshold the outcome they've asserted will become the new tentative winning outcome and there will be another window for reporters to dispute further. This process continues until a window passes with no dispute or until a fork occurs (once a dispute threshold is reached which accounts for 2.5% of the total REP supply).
The actual threshold for each dispute to be reached is provided by this formula:
2 * [ALL STAKE IN MARKET] - 3 * [STAKE ON ASSERTED OUTCOME]
This amount ensures that once a market is finalized the liquidated losing REP will provide a 50% ROI for the REP staked on the winning outcome.
So for example lets say the designated reporter shows up, and the required stake for them is 1 REP. They do the initial report and assert that outcome A is correct.
Once the fee window for the market begins reporters X and Y each contribute 1 REP to outcome B. Since the bond size for outcome B is
2 * 1 - 3 * 0 == 2 the dispute succeeds and the market's new tentative outcome is B.
If the market resolves here they will each receive their share of the 1 REP initially staked, thus giving them 1.5 REP total for their 1 REP stake.
If instead reporter Z stakes 3 REP on outcome A in the next fee window that bond will succeed since
2 * 3 - 3 * 1 == 3. In the event the market finalizes with outcome A now reporters X and Y will have their REP liquidated to pay the initial reporter and reporter Z. The initial reporter will get paid
1.5 REP and reporter Z gets