Most sports games determine a player's rating by their statistics average over the past few years. With the averaged statistics, they don't account for player match ups which can cause players to enter hot streaks and cold streaks. NHL 14 will bring the "Dynamic Ratings Updates" to more accurately represent real life player performance.
For Play Now sessions or Online head-to-head match ups, players will receive temporary boosts or drops to their statistics based on their performance. So if Phil Kessel enters one of his infamous dry spells and can only manage to find the goal post on every shot, his stats will receive an update to reflect his cold performance.
Likewise, if Phil Kessel scores 2 goals per game over the next few games, then his performance will temporarily boost his statistics. Cold and hot streaks will reflect with upward and downward pointing arrows next to the statistics of players when viewing the lineups.
Returning from NHL 13, the "True Performance Skating" system will provide greater responsiveness of players by allowing for quicker pivots on the ice. To cover more ground, lateral strafing will help on defence as the forwards push towards the opposing net.
NHL 14 will release September 10th for Xbox 360 and PlayStation 3 where Martin Brodeur will cover the game's box.