The [Chicago] impact zones, established in February 2013 after a violent 2012, comprise just 3 percent of the city's geographic area but account for one-fifth of its violent crime, according to the department.From the Sun Times:
In March 2013, the department began assigning foot patrol offers to the high-crime areas. McCarthy said feedback from the communities has been positive, as have the results. Since Feb. 1, 2013, in the impact zones, murders are down nearly 50 percent, shootings are down 43 percent and overall crime is down 26 percent, doubling and outpacing citywide reductions, he said.How is the different than NYC? Hopefully, one would think, the cops in Chicago are doing something other than feeling quota pressure to write citations.
In numbers, though, we're not talking many cops. 360 officers in total. 140 on bike 220 on foot. That's 18 cops per impact zone, which means about 4 or 5 on duty 16 hours a day. The zones seem rationally sized. The few I checked are about one-quarter to one-half square mile (or 30 to 55 blocks).