If I was trying to sabotage the rivals for a must win game going into the playoff season, you can’t do something that would be considered a normal prank like putting clear tape on the bottom of their blades. What I would do, I would start by loosening the screws on their skates so that they would fall off in the middle of the game rather than at the beginning. While equipment staff personnel are equipped to handle a blade coming off, I don’t believe they would be prepared for all of the blades coming off, or unscrewing them in a way that would result in the entire runner falling off for each player. Of course, the biggest problem would be if the goalie’s blades fell off as they have a lot more gear on and they would be in a much more difficult position to replace in a timely manner with all the other players having issues as well.