Forbes contributor John Tamny looks at the role safety equipment changes in the NFL plays in the rate of concussion-related injuries to players. This is a contrarian view of sports that most people don't take. Sports equipment is an interesting dynamic, and its relation to aggressive behavior is something I examined at The Hockey Writers over the course of the last season. Well, This Is Weird: Study Says NHLers Wearing Black Sweaters Are More Aggressive "To examine the color–aggression link, the authors analyzed the last 25 seasons of NHL penalty-minute data (649 seasons from 30 teams collapsed across 52,098 games). When teams wore black jerseys, they were penalized more than when they did not (d = 1.19; Study 1). When teams switched to wearing colored jerseys at home games, they were penalized more than when they wore white jerseys at home games (d = 0.83; Study 2). Collectively, these quasi-experimental findings suggest that black jerseys are associated with more aggression and that white jerseys are associated with less. The authors discuss possible causes for these color-aggression effects." Will New Concussion Detection Technology Improve Treatment and Prevention in the NHL? "So too could new injury analysis help inform the league’s progressively strict stance on head shots and other forms of questionable contact. Generally, new NHL chief disciplinarian Brendan Shanahan is helping to move the league forward in the prevention of brain and other forms of head injury, but a new wave of data analysis could help both the league and the NHLPA better and more consistently define what constitutes dangerous contact that doesn’t belong in the game of hockey." The Problem with Mandatory Visors in the NHL "We provide evidence of the Peltzman effect by tracking the professional path of each hockey player that ended up in the National Hockey League from 2001 to 2006. We take advantage of the fact that visor use has not always been compulsory throughout a player’s career, which allows us to compare the change in behavior of users and non-users of visors when they are forced to use them. We find that whereas the average penalty minutes per game is 0.8, visors cause a substantial increase of 0.2 penalty minutes per game. Players become more aggressive when forced to wear a visor, partially offsetting its protective effect and creating potential spillover effects to other players."