The last two cycles — 2008 and 2012 — have shown that the leader in the Republican delegate count at the point when 50percent of delegates have been allocated has been able to clinch the nomination around the point when 75 percent of thedelegates have been allocated. Although the process could easily resolve itself before that 75 percent threshold is met due towinnowing, this5075 percent rule is a reasonable approximation of when a candidate will clinch.On the likely primary calendar for 2016, March 8 would be the 50 percent point and April 26 would be the 75 percent marker.With that as a guide, we can work backward to an earlier point on the calendar when one candidate will be the remaining viablecandidate still in the race.How does how many votes a candidate gets in a state’s primary or caucus translate into how many of thatstates’ delegates are pledged to them?On the Democratic side, the national party mandates a proportional allocation of the delegates apportioned to each state. Themajority of states, in turn, utilize the results of their primaries or caucuses at both the statewide and congressional districtlevel to allocate and bind those delegates to the candidates who clear a threshold of the vote — which can be set no higher than15 percent — in those political units. If Hillary Clinton wins 60 percent of the vote statewide in the South Carolina primary, shewould receive around 60 percent of the atlarge and pledged party leader delegates. If she wins 60 percent of the vote in one ofSouth Carolina’s congressional districts, she would receive around 60 percent of the delegates apportioned to that district.The Republican National Committee is taking a similar approach for the states with primaries and caucuses that fall in the socalled “proportionality window,” defined as the first two weeks of March for 2016. The only difference is that the RNC allowsthe threshold for receiving any delegates to be set as high as 20 percent either statewide or in congressional districts.The RNC also allows a state party to institute a threshold for a candidate to receive all of the atlarge and bonus delegates. Inthose states that set such thresholds, if a candidate wins a majority of the vote statewide or in a congressional district, thatcandidate would be eligible to be allocated all of the delegates apportioned to that political unit.After March 14, state parties in the Republican process have the freedom to set their delegate allocation rules as they see fit.States can institute a proportional rule, a winnertakeall rule, or some hybrid. The differences between proportional andhybrid plans are typically so subtle that theydo not affect the delegate count.If states with contests after March 14 adopt a winnertakeall rule, that could create a de facto nominee sooner. However, in2012, there wasno such rush to winnertakeall rules among states with contests after the proportionality window.Have these rules about delegate allocation changed since 2012?For the Democrats, no.