• Teams get six mound visits per game, plus one for each extra inning played. That includes visits by the catcher and infielders. However, there are exceptions, including a pitcher-catcher conference between batters.

• Commercial breaks are shortened by 20 seconds, to 2:05 for regular season games, 2:25 for nationally televised games and 2:55 for postseason games.

• At the start of the inning, pitchers can throw as many warm-up pitches as they want before the timer runs out, though they are no longer guaranteed eight warm-up pitches.

• For commercial breaks, the timer begins immediately after the final out is recorded. During a pitching change, the timer begins when the reliever leaves the bullpen and crosses the warning track or foul line.

• There will be no automatic ball/strike penalties for timer violations. Players who violate the time limits could be disciplined.

• There is no pitch clock, even though a 20-second clock is used in the minor leagues.