They’re going, going … gone! MLB homers hit a 20-year low in 2014, due largely to expanded strike zones and tighter rules on performance-enhancing drugs. But last year they were outta the park, with 723 more home runs for a 17.3 percent jump — the odds for which were pegged at precisely zero by a sophisticated math program. Players have lots of theories, ranging from global warming and shortened fences to livelier balls and new maple bats. But it could be that batters are simply recovering from a really big slump.