Interesting tid bit for Buffalo the Sabres made the playoffs this past year and looking at the top 4 young dmen on the team they all had played over 200 games in the NHL to start the season.
Byram 328 games
Vlasic 260
Kaiser 175
Korchinski 105
Arty 86
Rinzel 63
Ethan Del Mastro 45
Based on this theory the Blackhawks are 2 years away from the playoffs, those dmen are babies.