The crime rate in the city has dipped so far this year and the New York Police Department is crediting Operation Impact, a program that sends police reinforcements into troubled neighborhoods.

“We keep crime down by staying focused through Operation Impact and through the continued hard work of the men and women of the NYPD,” Police Commissioner Raymond Kelly said in a statement released to The New York Sun.

According to the police department’s Compstat system, the crime rate slid 4.78% through October 3 of this year compared with the same period of 2003. The figure reflects a trend: Compstat shows a year-to-date drop of 10.18% over the last two years, a drop of 14.21% over the last three, and a plunge of 68.13% since the Compstat system was implemented in 1993.

The decline is based on the average tally of criminal complaints for the seven major FBI crime categories. Grand larceny auto had the steepest decline, at 11.2%, though grand larceny rose 2.4%. The homicide rate fell 8.2%, though some precincts at the Bronx and Brooklyn had notable increases.

These Compstat figures serve as valuable crime-fighting tools, and Mr. Kelly said they would be used to identify new targets for the deployment of fresh officers.

“We are also doing a better job at gathering and analyzing criminal intelligence,” said Mr. Kelly in the statement. “We want to apply that knowledge to attack violent crime in those few precincts where it has increased.”

By that measurement, Bedford-Stuyvesant’s 73rd Precinct is a leading candidate for more officers. The 73rd Precinct experienced the most substantial jump in homicides so far this year: an increase of 166.6%, to 24 murders, from nine during the 2003 period. Other trouble spots include the 46th Precinct at University Heights, where homicides jumped 128.5%, to 16 from seven, and the 60th Precinct at Coney Island, where homicides increased 75%, to 14 from eight.

Operation Impact was established last year with the express purpose of targeting violent neighborhoods, and crime dropped in the Impact Zones by one-third during the year of its inception, said a spokesman for the police department, Paul Browne. The program received additional funding in January, and 52 Impact Zones were established within 22 precincts, including 26 subway stations and nine housing developments. The zones generally cover a portion of a precinct, and can encompass an area as small as four city blocks or a single subway platform.

The police department uses fresh recruits to “flood the zones,” pairing rookies with experienced officers. Mr. Browne said two-thirds of graduating classes are typically deployed to Operation Impact, drawing from semi-annual classes of approximately 2,000 graduates.

The police department often does not wait for Compstat figures to come out. Neighborhoods hit by spates of shootings, fatal or nonfatal, during any given weekend are likely to receive an influx of new officers.

“Shootings are generally our overall measurement of crime,” said Mr. Browne. “We tend to use shootings, whether they result in homicides or not, as a general indicator of where we put Impact” officers.

Mr. Browne said that more than two thirds of the citywide decline in crime can be directly attributed to Operation Impact, and that the number of neighborhoods targeted by the operation can shift constantly. Police officers move into neighborhoods as crime climbs, and when crime declines they move on to tackle other trouble areas.

Police department statistics bear out the effects of Operation Impact. In the recent year-to-date figures available, murders, shootings, and robberies fell 8.6% citywide through August 1; those crimes plunged 27.4% in Impact Zones.

Operation Impact had its biggest effect in Queens, where murders, shootings, and robberies in the Impact Zones fell 34.2% through August 1, driving a boroughwide decline of 14.4%, according to police. Brooklyn also felt the effects, with declines in those crimes of 30.5% recorded in the Impact Zones, contributing to a boroughwide reduction of 10.3%.

Citywide, the number of murders dropped 9.9% through August 1, led by a 27% reduction in the Impact Zones, according to police. The reduction in killings was felt most strongly in Brooklyn, where a 69% decline in the Impact Zones contributed to a 7.8% drop boroughwide.