The New York primary is rather 28 separate primaries, as 81 of the delegates will be distributed on the basis of results in the state's 27 congressional districts and 14 will distributed at large based on the statewide results.  It takes winning over 50% of the vote to be allocated all three delegates from a district.  If the winner has a mere plurality, the delegates are allocated proportionally.  These 27 districts include urban minority enclaves, affluent suburbs, small cities, and vast stretches of rural areas. 

Another crucial factor is that New York is closed primary: not only can't independents participate in the party primaries, but there is an exceptionally long lead time for changing party affiliation.  While new voters could register by March 25 and qualify to vote on April 19, the deadline for those who were already registered to change their party affiliation was October 9, 2015.  

These rules may make for some unusual calculations on how a candidate may want to allocate resources.  For example, winning 4,000 votes in the 17th Congressional District means winning more delegates than winning 80,000 votes in the 27th District because there are only 7,500 registered Republicans in the former, while there are 186,000 registered Republicans in the later.  Because most of the delegates will be allocated based on results within each district and because the districts are so diverse, this is a contest that calls for a good internal polling operation and a strong local organization to allocate resources to the most promising districts.