The Blues, and teams like them, have tended to neutralize the Stars' speed with their superior defensive positioning and constant forecheck successfully turning it into a grinding style game. The Stars seem to do best against teams that play a more open system. In fact I'd say St. Louis is the Stars' worst matchup in the West. The fact that they've taken over the top spot from the Ducks is worrisome.
ehh I don't really agree about that, in both of the previous games against the Blues Dallas had a big edge in the shots, and possession time. We should have won that game in Dallas by 2 goals, it was only their goaltender stealing the game for them. The only other teams that play a really similar slow / grind it out / possession based game at a similar level to the Blues are Los Angeles (who we have looked good against this year) and New Jersey (not so much on the looking good front). The vast majority of teams are somwhere in the middle, and I don't think there's been a large enough sample of games against teams that play extreme defensive hockey to suggest if that is actually something Dallas struggles against. I mean part of the reason there is a small sample size is that teams that have traditionally relied upon that style of play like Nashville, Minnesota, Phoenix, and Calgary have either been too bad to pull it off this year or have moved to much more wide open playing styles.
I think that every time Dallas is low on energy and has a slow game it gets attributed to the other squad playing "tough defensive hockey" instead of Dallas having an off night. I kind of wonder if that creates the false impression that the key to shutting down Dallas is playing a certain way, whereas the nights they overcome teams that try to pull that defense against them (the recent game against Carolina comes to mind) nobody notices that the other team is playing very passively and attempting to shut down the Stars without much success.
Back on topic, St. Louis has benefited massively from the highest shooting percentage in the league this year, and that luck has been there in both of their games against the Stars so far. It makes them look a whole lot more dangerous than they actually are - the shooting luck has started to go away recently, and every game they've played in the last 10 or 15 has basically come down to the last minute or overtime - even when they've played some of the weaker teams. I think Dallas will be in this one until the end, and has a good chance of taking points.