As has been suggested for the past few years, the lower end of the strike zone will be raised to the top of the knee. In addition, I suggest the top should be raised to the bottom of the shoulders based on the player’s natural batting stance.
Inside and outside pitches will be called strikes if they are within one ball length of the plate. Call it the Tom Glavine Rule.
This should result in more balls in play because we all know that no one can hit a slightly below the knee slider from Jacob deGrom or Noah Syndergaard. Adding to the top will reward the best pitchers and cause the lesser pitchers to give up more contact.
Each manager gets one challenge for the first six innings.
Everything except balls and strikes can be challenged. The home plate umpire wears an earpiece/mic that allows instant communication with the league office, so reviews start as soon as a close play happens.
If the call is challenged, the league office has a head start on the review. The home plate umpire stays at home plate, hears the review result, and announces it as soon as possible.
From the seventh inning on, the league office reviews every close play immediately and tells the home plate umpire to wait a few seconds before resuming play. If the call is overturned, the home plate umpire announces it as soon as possible.