NEW YORK • For decades, spying on another team has been part of baseball's gamesmanship.
The Boston Red Sox have apparently added a modern - and illicit - twist: They used an Apple Watch to gain an advantage against the New York Yankees and other teams.
Investigators for Major League Baseball have determined that the Red Sox executed a scheme to illicitly steal hand signals from opponents' catchers in games against the Yankees, according to several people briefed on the matter.
The baseball inquiry began about two weeks ago, after the Yankees' general manager, Brian Cashman, filed a detailed complaint with the commissioner's office that included a video the Yankees shot of the Red Sox dugout during a three-game series between the two teams in Boston last month.
The Yankees, who had long been suspicious of the Red Sox stealing catchers' signs in Fenway Park, contended the video showed a member of the Red Sox training staff looking at his Apple Watch in the dugout and then relaying a message to players, who may have then been able to use the information to determine what pitch was going to be thrown.
Baseball investigators corroborated the Yankees' claims based on video the commissioner's office uses for instant replay and broadcasts, the people said.
The commissioner's office then confronted the Red Sox, who admitted that their trainers had received signals from video replay personnel and then relayed that information to some players.
It is unclear what penalties, if any, commissioner Rob Manfred will issue against the Red Sox and whether he will order a more expansive investigation to determine the extent of the Red Sox's system.
"We will conduct a thorough investigation on both sides," Manfred said. "We're 100 per cent comfortable that it is not an ongoing issue."
Stealing signs is believed to be most effective when there is a runner on second base who can watch what hand signals the catcher is using to communicate with the pitcher and then relay these clues to the batter.
Such tactics are allowed as long as teams do not use any methods beyond their eyes. Binoculars and electronic devices are prohibited.
In recent years, as cameras have proliferated in major league ballparks, teams have begun using the abundance of video to help them discern opponents' signs.
Some sides have had clubhouse attendants quickly relay information to the dugout from the personnel monitoring video feeds.
The information has to be rushed to the dugout on foot so it can be passed to the runner while he is still on second base.
The Red Sox seemed to hasten this process - and quickly get the information to the runner on second and the hitter at the plate - by sending information electronically to team members in the dugout.