A penalty given to a player who checks the head of an opponent and the head is the principle point of contact.
In 2011 the National Hockey League - NHL changed Rule 48 to allow officials to penalize any check to the head where the principle point of contact was the head. After not allowing checks to the head laterally or from the blind side, the league now allows referees to call minor penalties for violation from the rule and eliminated laterally and blind side.
Matt Cooke is recognized as one of the biggest reasons for altering of the rule in 2010 to expanding it in 2011 after hits to Marc Savard and Ryan McDonagh - the latter being a suspendable offense due to the rule change. The Savard hit meanwhile occurred before the new rule was written in March 2010.