Seymour Siwoff, Master of Sports Statistics, Is Dead at 99

“We’ve got more information on sports up here in our office than they do down there,” he once said.

Elias has over the years been joined by a growing field of statistical compilers and analysts. But it retains its standing as the official statistician for many leagues.

Seymour Siwoff was born on Nov. 9, 1920, in Brooklyn to Jack and Ida Siwoff and grew up in the Brighton Beach section. His father made women’s shoes.

In his early years at Elias, Mr. Siwoff delivered updated statistics for the major leagues’ batting and pitching leaders to New York newspapers and wire services like The Associated Press after the bureau combed through daily box scores.

Long after his data was computerized, Mr. Siwoff retained something of an old-time aura.

“His slight, angular frame is covered by conservatively cut business suits,” The Hartford Courant reported in 2004. “He always wears a tie and leather shoes with laces, of course, even in the summer. In the winter months comes the overcoat and fedora. His reed-thin mustache is right out of Ronald Colman or William Powell.”

In 1975 Mr. Siwoff began publishing The Player Analysis, printouts weighing some 40 pounds, for about a half-dozen major league baseball teams. The teams paid Elias to assess each of their players’ performances in a host of situations.

From 1985 to 1993, Elias put out a successor publication, the annual Elias Baseball Analyst, which was sold to the public. It has long issued The Elias Book of Baseball Records, an annual publication also available for purchase.

In addition to Mr. Gilston, Mr. Siwoff is survived by a son, Ronald; a daughter, Nancy Gilston; three other grandchildren; and two great-grandchildren. His sister Lela Swift, a pioneering female director whose career went back to television’s early years, died in 2015 at 96.