Every year, following the holidays Dellin Betances trades the harsh New York winters for the Dominican Republic’s warmth. There, the four-time All Star reliever punishes his 6-foot-8, 265-pound frame with conditioning drills and participates in a throwing program as spring training approaches. But next month’s program will be more specific for the 30-year-old right-hander who faded in the latter part of 2017 when control problems surfaced. “My fastball command will be one of my focus points when I go to the Dominican,’’ Betances said Wednesday at Yankee Stadium, where the Yankees held their 24th annual Holiday Food Drive. “It was a little bit last year but I will focus on it a little bit more. Working on my fastball will be huge this offseason. If I get back on track, everything will take care of itself.’’ For a fourth straight season, Betances was an AL All-Star but September and October brought control issues. In a dozen September games, Betances worked 9²/₃ innings and recorded 15 strikeouts, which was very good and much in line with his career. Nevertheless, he issued seven walks and posted a 5.59 ERA despite limiting batters to a .176 average. In five postseason games, Betances struck out six in four innings but walked five, which negated a .154 batting average against. For the season, Betances worked 66 games, the fewest since he became a big-league regular, posted a 2.87 ERA, allowed 29 hits and fanned 100 in 59 ²/₃ innings, but walked 44. Whenever Betances hits a rough spot, mechanical problems are usually the cause because there is a lot more body movement in a 6-8 pitcher than a 6-footer.