But what hasn't happened in that 21-month span, despite all the uproar in the wake of Posey's injury, is a substantive change to MLB's rules regarding home-plate contact.
The conversation, though, is ongoing, as evidenced by Cardinals manager Mike Matheny's request for a meeting with MLB executive vice president of baseball operations Joe Torre to discuss the matter.
Matheny is a convert to the school of thought that such contact (I try to stop short of referring to them as "collisions," given that only one party is actually moving) are a dangerous and unnecessary part of the game.
"I do believe that this game will get to the point where there will no longer be a collision at the plate," Matheny told reporters Tuesday. "And I am 100 percent in support of that."
Though he suffered an estimated 25 to 30 concussions in his own career -- with many of those concussions coming as a result of hard hits at the plate -- Matheny's stance shifted not as a result of his own playing experience but rather the experience of stepping into a managerial role. Any question about whether his old instincts had gone out the window was answered when he watched, wincing, as $75 million catcher Yadi Molina got trucked by the Pirates' Josh Harrison last summer.
"I understand old-school, and I consider myself an old-school player, as far as the way I go out and the way I was taught the game," Matheny said. "[But] I just don't see the sense in it."
The notion Matheny is supporting is a noble one. This is, after all, not inherently supposed to be a contact sport, a violent sport. And the increased awareness about the dangers of head injuries opened the door to better protection for MLB players -- from the seven-day disabled list for concussed players, introduced in 2011, to the stronger batting helmets introduced this spring.
Home-plate contact, however, is a much more difficult matter to police, and I'm not sure there's an easy answer here.
Some of the proposals set forth to prevent catcher injuries look much better on paper than they do in reality, where competitive instinct and basic human error are involved.
For instance, one popular proposal dictates that the runner not be allowed to initiate contact with the catcher if the catcher has control of the ball. That's all well and good, in theory. But in real time? In the sometimes milliseconds between the catch and the contact? What runner can make that differentiation that quickly?
Another popular proposal is to allow catchers to block the plate only if they have full control of the ball. But this assumes that every throw will be on-line and no throws will pull a catcher into the path of the baserunner (a bold assumption).
Actually, Rule 7.06 already dictates that obstruction be called if a catcher blocks the plate without possession of the ball or while not in the process of "fielding" the ball. Alas, this rule is largely ignored, because the determination of what constitutes "fielding" is ultimately a judgment call, anyway. So while it's easy to call for a stricter enforcement of that rule, it's difficult to actually apply it.
No, the only proposal with any meat on the bone is one that outlaws collisions completely -- the "slide or avoid" rule employed at the amateur levels.
It's an either-or equation, and it makes for a contentious conversation.
The most popular rebuttal to Matheny's mindset is a simple, "It's part of the game and has been for a long time." On its own, this is not an effective debate position, obviously, as there are plenty of elements of the game -- from outfield fences without padding to hitters without helmets to dugouts without railings -- that were once accepted as the norm, only to be altered in a bid for player safety.
But given that Rule 7.06 already grants the baseline to the runner, how do you prevent that runner from doing whatever is necessary to reach home plate? You can't expect him to stop dead in his tracks simply because the catcher has possession of the ball. And even if you dictate that catchers must give up part of the plate to a sliding runner, there are certainly ways in which a slide could be forceful, to the point where the umpire would have to make a determination as to whether it was inherently reckless.
You can see where that could diverge into the kind of "flagrant foul" or "unnecessary roughness" judgment call ground on which baseball arguably ought not tread.
So that's why nothing has changed with regard to this rule in the wake of the Posey injury, just as nothing changed after the Ray Fosse injury or the countless other violent episodes that have taken place at the plate over the years.
This is a tricky one. It would seem the best a mindful manager like Matheny can do in the meantime is to instruct his catchers to stop blocking the plate at all costs, as the Giants have done with Posey. But even that is an imperfect arrangement, of course, as instincts do tend to take over in the heat of battle.
There are passionate takes on both sides of the argument, and it would be interesting to be a fly on the wall when Matheny and Torre do get together and dish about the dish. But I'm not sure we're anywhere near as close to a game without collisions as Matheny would like us to be.