The Boston Red Sox are becoming familiar with Major League Baseball's Automatic Ball-Strike system, which became part of the system at the start of spring training. Teams start each game with two challenges, with each player remaining free to challenge again if they successfully. The Red Sox have challenged 24 times, with a 46% success rate (11 for 13) so far. Red Sox catchers have challenged 27 times, while pitchers Carlos Narvaez and Connor Wong have been successful in defensive challenges. Willson Contreras, Boston's new first baseman, leads American League hitters with five challenges, tied with Yankees' Jose Caballero for the most in the majors. The Los Angeles Dodgers have been the least successful team in the ABS era, with their catchers' challenge rate at 3.