Thanks largely in part to a Buster Posey broken leg and that infamous Chase Utley takeout slide in the playoffs at second base, Major League Baseball has changed the rules around slides into bases and taking out the catcher at home plate in recent years. On Monday in Pittsburgh, Cubs first baseman Anthony Rizzo slid into Pirates catcher Elias Diaz on his way to home plate and it sparked a big discussion on social media about whether or not the slide was dirty and/or should be illegal. 

Here it is, including the review which determined the play was legal: 

Here's the slide rule, directly from Major League Baseball: 

When sliding into a base in an attempt to break up a double play, a runner has to make a "bona fide slide." Such is defined as the runner making contact with the ground before reaching the base, being able to reach the base with a hand or foot, being able 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. The slide rule prohibits runners from using a "roll block" or attempting to initiate contact with the fielder by elevating and kicking his leg above the fielder's knee, throwing his arm or his upper body or grabbing the fielder. When a violation of the slide rule occurs, the offending runner and the batter-runner will be called out.

Accidental contact can occur in the course of a permissible slide, and a runner will not be called for interference if contact is caused by a fielder being in the runner's legal pathway to the base.

It's interesting that MLB determined the play legal here. Yes, Rizzo was able to touch home plate and it was a slide in which he didn't kick his leg upward, but he did change his path. After the game, Rizzo said he was just trying to break up the double play, so that pretty clearly shows he did intentionally slide toward the catcher, not accidentally. 

Still, Rizzo definitely got all of home plate and didn't elevate his legs at all. That's probably why the ruling came down in the Cubs' favor. 

The hunch here is that Rizzo won't be disciplined -- how could they discipline someone when they ruled the play legal? -- but that there's discussion about possibly adding some language to the rule to forbid this type of a play in the future. 

As far as any animosity between the two teams, if what Rizzo says here is true, there likely isn't: 

Time will tell. The two teams square off again Tuesday in PNC Park.