Athletes who have had rules changed or made based on them...

The NFL banned the clothesline tackle after Night Train Lane made it his trademark. Same with Roy Williams, who broke more legs than a pissed-off bookie with the horse collar tackle.
The NFL's last rules tweak in the passing game came because the Patriots were abusing receivers at the line.

MLB adjusted its rules on elbow pads and such when guys like Bonds, Biggio and Mo Vaughn were wearing oversized pieces of armor to the plate. A similar rule was passed in the NHL when some goalies were wearing pads that were oversized.

 

Ray Chapman.

Not necessarily a "rules change" as such, but his death essentially led to spitballs being outlawed, and to more frequent switches of the baseball so a clean white one, not a scuffed one, was in use.

Tony C. and others who were beaned led to the implementation of the earflap for baseball helmets.

 

From a certain time until the mid 80s, NHL rules saw teams play 4-on-4 when players from both teams received coincidental minor penalties. In the mid-80s, the league went back to 5-on-5 in that situation, apparently due to the Oilers' dominance in 4-on-4.

The league went back to 4-on-4 a while back.

Also, not an on-ice change, but Eric Lindros' refusal to report to the Sault Ste. Marie Greyhounds in 1989 (the junior team that drafted him as a 16-year-old) led the Ontario Hockey League to change its rule that prohibited teams from trading their most recent first-round picks. The league instituted a rule allowing those players to be traded from January 1-10 each year, and Lindros was traded from SSM to the Oshawa Generals.

 

Probably not a direct change but Pete Reiser's continued collisions with outfield walls led to creation of the warning track.

 

Similarly, the mid-century Habs wore everyone out with the power play so much that they started truncating minor penalties after a goal is scored.

In the SEC, Nick Saban inspired the rule that now prohibits head coaches having contact with recruits during the spring. And the new league limit of 28 signees for football is the Houston Nutt Rule.

 

That's the one I was thinking of.

 

Dwane Casey is the reason Kentucky only uses UPS now.

 

Sean Avery was the first one I thought of, waving his stick in the goalie's face.

Also, European soccer's equivalent of free agency is the Bosman move, named for Belgian player Jean-Marc Bosman.

 

Isn't that the J.S. Giguere rule?

 

From the way-back machine:

Germany Schaefer famously "stole first base" in a major league game, leading to a rule change outlawing that play.

But the story told in "Glory of Their Times" is not entirely accurate:
http://bioproj.sabr.org/bioproj.cfm?a=v&v=l&bid=1734&pid=12553

 

Would it be rude to tell this guy to sit on Google for an hour to find this stuff? And guess what, outside of Long Island, Baltimore, Colorado and one or two other pockets, no one gives a shit about lacrosse or knows any of its history.

You seem to not have a problem being rude.

 

So much so, I often heard it referred to as "The Gretzky Rule."

You can also argue the outcry in Buffalo after Brett Hull's game-winning goal for Dallas in the 1999 Stanley Cup Finals directly led to an amendment of the "in the crease" rule.

And since somebody mentioned Tom Brady earlier, I'm surprised nobody mentioned his (ahem) "incomplete pass" in the playoff game against Oakland and its effect on the "tuck rule."