Short of stature -- about 5-foot-7 -- and rotund, 46-year-old Jack Maple is given to wearing two-tone shoes, striped shirts, bow-ties and a homburg hat. But don't let his taste in clothing fool you. He cut his stylistic teeth in New York City's hot lunch spots, while cutting his professional teeth underground, in what New York's finest derisively refer to as the caves.

The caves are the New York subways -- once considered as dangerous a place as any in the world. In the 1980s, Maple was an aggressive transit cop who moved up to the rank of transit lieutenant. When he got tired of responding to crime instead of fighting it, he went home and put his unschooled but analytical mind to work.

"I called them the Charts of the Future. On 55 feet of wall space, I mapped every train station in New York City and every train," Maple recently explained. "Then I used crayons to mark every violent crime, robbery and grand larceny that occurred. I mapped the solved vs. the unsolved."

Later, when William Bratton was hired by the Transit Police to cut crime, Maple showed him the charts, and between 1990 and 1992 they cut felonies in the caves by 27 percent and robberies by a third.

In 1994, when Bratton was appointed by Mayor Rudolph Giuliani to head the NYPD, the new commissioner made the flamboyant Maple his second-in-command. The move, likened to promoting a Navy ensign to admiral, ruffled many feathers. But using computerized Charts of the Future, precinct commanders were held accountable for crimes in their area. For the first time that anyone could remember, crime in New York City began to decline.

COMSTAT was born. COMSTAT is a process by which crime statistics are collected, computerized, mapped and disseminated quickly. Officers are held responsible for the crime in their areas, and all crimes, including the "quality of life" infractions like loitering or public intoxication, are pursued aggressively. The program has become the talk of squad rooms nationwide.

Today, Maple is a high-paid consultant, with his partner John Linder, being hired by major cities, including New Orleans, Birmingham, Ala., Philadelphia, Newark, N.J., and Jackson, Miss., to break the grip of criminals. In every case, they are seeing results similar to those in New York City, while other communities are adapting the process without Maple's help.

Still, there are detractors who claim COMSTAT's dramatic success in what was once the country's most corrupt and dangerous city has more to do with a decline in the numbers of juveniles nationwide, heavy-handed prosecution policies and the increase in the number of cops on the street, than with Maple's computerized strategies.

For those detractors, Maple provided a typically direct answer and a challenge.

Q: A lot of people don't want to give COMSTAT full credit for the dramatic decline in crime rates in New York City. What is your response?

A: Across the nation, murder is down 21 percent. In New York, murder is down 70 percent. Everyone thinks crime is down a lot in America. Well, guess what? Across the nation, with New York removed, crime is down 8 percent. Whoopee. In 1961, murder, rape and robbery was 158 per 100,000. Now it is 570 per 100,000 -- three-and-a-half times higher. Sometimes people build a fool's paradise.

The juvenile population from 1990 till now went up in New York. They have their statistics wrong, as usual. Between 1980 and 1990, while crime was going up, the juvenile population went down. In the 1990s, when we were implementing COMSTAT, it was the opposite. So they don't know what they're talking about. And I'd like to know how demographics change within a single year. In 1995, New York City accounted for 68 percent of the crime decline in America, even though they only have 3.3 percent of the crime.