After the 2000 census, New York had 29 representatives. The first four districts were all located on Long Island in the counties of Suffolk and Nassau. The Fifth District included parts of Queens and Nassau. The next eleven districts were entirely within New York City. The Seventeenth District included parts of the Bronx and Rockland County. The other twelve districts headed gradually north and west through “upstate” New York with the Eighteenth and Nineteenth being the immediate suburbs, the Twentieth, Twenty-first and Twenty-second being the next ring out, the Twenty-third being northeast New York reaching the Canadian border, the Twenty-fourth being central New York, the Twenty-fifth being the area around Syracuse, and the other four districts composing the western part of the panhandle of New York.
After the 2010 Census, New York has lost two seats and is down to 27 representatives. The new target number is 718,000.
At a quick glance, Nassau and Suffolk are going to be about 39,000 short of an even four representatives. So instead of being wholly in Nassau, the Fourth will not take in part of Queens or Brooklyn. The Five Burroughs of New York City combine for a total population of 8,175,133 which works out to just over 11 representatives with 277,000 excess. In other words, after giving 39,000 to the Fourth District, the last complete New York City district will be the Fifteenth, and the excess 238,000 will be going into the Sixteenth rather than the Seventeenth.
Looking at the current map, districts six through twelve are all wholly contained within Brooklyn and Queens with district 13 being split between Brooklyan and Staten Island, and district fourteen being split between Queens and Manhattan. With the new numbes, Queens, Brooklyn and Staten Island, have a little over seven representatives combined with 178,000 left over. That means that after dumping the extra 39,000 into the fourth, the last whole district withing Queens, Staten Island, and Brooklyn will now be the Eleventh rather than the Thirteenth. Bottom line — one of the two representatives to be dropped is coming from Queens and Brooklyn.
For the remainder of the state, the numbers do not make for an district that is being cut. Rather it will be a case of a slow adjustment heading out of New York City and the far Western side of the state. Of the thirteen current districts wholly or partially in upstate New York, they range in size from the Nineteenth (just under 700,000) to the Twenty-eighth (around 612,000).
As best as I can guesstimate, the new Sixteenth and Seventeenth will be composed of the northern Bronx plus Rockland and Westchester Counties (basically the current Seventeenth and Eighteenth with some minor adjustments). There will be an excess 63,000 to go into the new Eighteenth. Likewise, the old Nineteenth (composed of the remainder from Rockland and Westchester, plus part of Orange, Putnam, and Duchess County) will be the new Eighteenth. There will be 115,000 excess from part of Orange and Duchess to go into the neighboring district.
From this point on is where things get tricky. Currently the excess from Orange and Duchess is split between the Twentieth and the Twenty-second. Both districts (and the Twenty-first) also contain other partial counties. Schenactady (in the Twenty-first) and Saratoga (in the Twentieth) were among the faster growing counties in New York). My hunch says each of these districts bumps a little bit northward and westward.