New rules redefining what constitutes a legal slide while trying to break up a double play and two additions to the pace-of-game initiatives have been agreed to by Major League Baseball and the Major League Baseball Players Association.

The slide rule is intended to protect infielders while still allowing for aggressive baserunning. The latter continues efforts, which began last season, to improve the tempo of games.

Here's the skinny on what you need to know:
THE SLIDE RULE

The basics: In the past, runners were given wide latitude coming into second base as long as they were close enough to touch the bag.

Under the new Rule 6.01(j), a runner will have to make a "bona fide slide," which is defined as making contact with the ground before reaching the base, being able to and attempting to reach the base with a hand or foot, being able to and attempting to remain on the base at the completion of the slide (except at home plate) and not changing his path for the purpose of initiating contact with a fielder.

This issue rose to the forefront during the 2015 postseason when Chase Utley broke up a potential double play in Game 2 of the National League Division Series with a controversial slide that ended up injuring Mets shortstop Ruben Tejada.
A runner may still make contact in the course of a permissible slide, but is specifically prohibited from using a "roll block" -- think Hal McRae in the 1977 American League Championship Series -- or intentionally initiating (or attempting to initiate) contact with the fielder by elevating and kicking his leg above the fielder's knee or throwing his arm or his upper body.
• Mets skipper Collins weighs in on rule change
Violators will be called out for interference, and the batter-runner will also be called out. Interference will not be called, however, if the contact is caused by the fielder positioning himself or moving into the runner's legal path to the base.

Potential violations will be subject to instant-replay review, as will "neighborhood plays," in which a middle infielder straddles the base or glides past it on a double-play pivot. That play was previously not eligible for replay review, and this change will mean an end to the tactic, meaning middle infielders will need to touch the base while in possession of the ball when turning a double play. If they don't they risk the umpiring not giving them the out or the opposing manager issuing a challenge.
What they're saying
• Utley: "[The old slide rule] is all I've known for a while, so I imagine there will be a little part of adjustment, not only for infielders but baserunners and umpires. It's like the plate rule and batter's box rule [changes]; it takes awhile to get comfortable."
• Utley: New slide rule will take adjustment
• Rangers SS Elvis Andrus: "I love it as a fielder but I hate it as a runner."
• Astros manager A.J. Hinch: "Obviously, there's been a few injuries the last year. There's a few new additions that won't really change the way we play, but maybe change some of the extreme slides we've seen throughout the years."
• Pirates manager Clint Hurdle: "I think the intent was in a good place. I think it's working for the betterment of the game. You're not going to be able to make any contact above the knee. I think these guys are going to have to slide a little bit earlier, so I think it's a definite step in the right direction."

• Tony Clark, executive director of the MLBPA: "Our goal in amending the slide rule was to enhance player safety, reduce incidents of injury and to do it in a way that respects and preserves the bona fide hustle plays that are integral to our game. I am optimistic that this new rule will accomplish those goals."
• Pirates SS Jung Ho Kang, whose season was ended on an aggressive slide by Chris Coghlan: "I'm all for it. It's safe for the players, safe for the players who are in the double-play situation. It's for the players, to protect the players."
• Mercer, Kang appreciate new slide rule
PACE OF PLAY/MOUND VISITS
These changes come with less fanfare, but may have a more tangible impact on the fan's viewing experience.
The basics: Visits to the mound by managers and coaches -- which previously had no time limit -- will be limited to 30 seconds and between-inning break times will now match the commercial time: 2 minutes, 5 seconds for local broadcasts and 2 minutes, 25 seconds for nationally televised games. The break times were 20 seconds longer last season, but the change is expected to allow the resumption of play to more closely match the end of the breaks.
The timer for mound visits will be the same in-stadium clock that measures the between-inning breaks. The timer will be set at 30 seconds and will begin counting down when the manager or coach has exited the dugout and the timeout for a mound visit has been granted by the Umpire. Unless the manager (or coach) signals for a pitching change, he must leave the mound when (or before) the timer reaches "0" (zero) seconds.
In 2015, MLB instituted a few pace-of-play measures that had a significant impact on time of game. The focus of these changes revolved the aforementioned clocks between innings and keeping hitters in the batter's box. Almost all of last year's pace-of-game initiatives, which helped reduce the average game time by 6 minutes, 7 seconds per nine-inning game, will continue.
The World Umpires Association signed off on the latest changes.
What they're saying
• Tony Clark: "Last year's pace-of-game experiment yielded positive trends that we hope to repeat in 2016. Our agreement for this year carries forward rules that were effective last season, and also introduces some new concepts that are aimed at making further improvements. Most importantly, we received and relied upon on tremendous input from players all across the league who care deeply about striking a balance between promoting our game and protecting its fundamental character."

• Giants manager Bruce Bochy: "I'll be doing some sprints in spring, you'll see me on the back field. But seriously, that's plenty of time from the time you leave the dugout. I don't see it being an issue."
• Reds manager Bryan Price: "This issue is the timing starts as soon as they see a coach or a manager leave the dugout. So it's not getting to the mound and having 30 seconds. It's from the time you leave. What it is doing is encouraging your coach or manager to jog out -- if he's not making a pitching change -- to jog out, try to hustle, say whatever you're going to say and get back ... But quite often you're trying to impart something that will change to direction of tide. That might take more than 20 or 22 seconds [plus time to get to and from the dugout]."