MLB nine-inning games this season are taking six minutes longer than they did through the same number of games last season and are on pace for the longest average game time in the four seasons under the pitch timer. But don’t be so quick to blame ABS. The ABS challenge system, in which the batter, catcher and pitcher can ask for a review of the umpire’s ball or strike call, has added 63 seconds per game, based on an average of 4.1 challenges per game. The first 421 games this year have clocked in at an average of 2:43, as compared to 2:37 through the first 421 games last year. That’s still faster than in any full season before the pitch timer since 1984. The reasons for the added time are more nuanced than pointing the finger at ABS. Here are some of those reasons: There are five more pitches per game, from 289 last year to 294 this year. The early increases this year in the strikeout and walk rates (call it the ABS break-in period) have flattened.…