Not immediately it won't, because players have to re-learn technique, but over time as proper technique is emphasized and learned, concussions will drop. You keep acting like one effeort has to be 100% effective or its not worth doing, but nothing works that way. DUI laws don't eliminate 100% of traffic accidents, or even alcohol-related accidents, but should people plastered out of their minds be allowed to drive just because traffic accidents are going to happen anyway? That is dumb logic. If we have a chance to eliminate even just some percentage of injuries that are life destroying for people like Aaron Hernandez and Junior Seau we should take that opportunity.