Rules changes and modifications: What they mean

Several modifications have been made to the rule book going into the 2017 season. Though Major League Baseball and the MLB Players Association haven't agreed to an adjustment to the strike zone or grand-scale changes that might dramatically alter baseball as we know it, the seven tweaks announced on Thursday do have implications.
Let's address them here:
The change: The adoption of the no-pitch intentional walk. The manager will signal to the home-plate umpire his decision to intentionally walk a batter, and the umpire will immediately award first base to the batter.
What it means: Gone are the occasional occurrences in which a wild pitch on an intentional walk or a surprise swing at an intentional ball would actually affect outcomes. Though this will likely have very little impact on game times (there were only 932 intentional walks in 4,856 games last year), the change is one small part of an ongoing effort to improve pace of action.

The change: Managers will have a 30-second limit to decide whether to challenge a play and invoke a replay review.
What it means: No more milking it. Though the rule book already called for a manager to "immediately" inform the umpire whether he wishes to issue a challenge, suffice to say the letter of the law was not strictly enforced. There were often long delays as managers waited on word from their internal replay assistants before challenging. The key word here could be "limit," as opposed to "guideline." Assuming proper enforcement, this rule will compel clubs to speed up their challenge processes.
The change: When a manager has exhausted his challenges for the game, the crew chief may invoke replay review for non-home run calls beginning in the eighth inning, instead of the seventh inning.
What it means: A manager still gets one challenge per regular-season game, retaining that challenge if a challenged call is overturned (managers get two challenges in the postseason). This tweak could make them just a wee bit more cautious with how that challenge is deployed, because umpires won't be able to step in and "save" a manager who is out of challenges until the eighth.
The change: With various exceptions, replay officials in the Replay Operations Center in New York will have two minutes to render a decision on a replay review.
What it means: The news release from MLB and the Players Association did not make clear what the exceptions would be, though one would assume that relates to the delay that often precedes the availability of super-slow-motion feeds necessary in the most difficult of reviews. Though this adjustment won't affect most reviews (the average review time was a record-low 1 minute, 36 seconds last year), it will purportedly prevent the especially lengthy ones.

The change: Teams may not use any markers on the field as points of reference for fielders' defensive positioning.
What it means: This subject became newsworthy last May, when the Mets contacted MLB about a Dodgers request to make marks on the Citi Field grass to identify desired positioning for their outfielders. Rules 3.09 and 3.10 prevent clubs from leaving equipment on the playing field, but this modification makes it clear that these specific kinds of markers are prohibited.
The change: An addition to Rule 5.07 stipulates that a pitcher may not take a second step toward home plate with either foot or otherwise reset his pivot foot in his delivery of the pitch. If there is at least one runner on base, then such an action will be called as a balk under Rule 6.02(a). If the bases are unoccupied, then it will be considered an illegal pitch under Rule 6.02(b).
What it means: Is this the Carter Capps Rule? We'll see. The Padres reliever's unusual and controversial hop-and-drag delivery has been in question since his 2015 arrival to the big leagues. Padres manager Andy Green told reporters on Thursday that the team will stay in touch with MLB regarding whether this rule affects Capps, though their current understanding is that as long as he limits himself to one "hop" and drags his pivot foot (as opposed to "resetting" it), Capps is in the clear. But because Capps has found a way to essentially shorten the distance between the mound and home plate, his situation continues to merit monitoring.

The change: An amendment to Rule 5.03 requires base coaches to position themselves behind the line of the coach's box closest to home plate and the front line that runs parallel to the foul line prior to each pitch. A base coach may leave the coach's box to signal a player once a ball is in play, provided the coach does not interfere with the play.
What it means: You see that coach's box? Get in it, coaches!