Lindy Ruff isn't a man known for adhering to analytically inspired systems of team management. He is known as a guy that doesn't take many pains to manage zone starts for his players, and the undertones of most stories written about Ruff tend to, at least in my opinion, frame Ruff as a coach who doesn't worry so much about exploiting match ups.
I think that is an oversimplification of Ruff's style. These things are never black and white. I think a more appropriate description would be adaptable. The four tables below are the Sabres primary defensemen from 2009 to 2012. For each player you will find Quality of Competition and Offensive Zone Start %. 2013 isn't included since Ruff lost his job mid-season.
The first thing that jumps out of the usage pattern for 2012 is the relatively small range of values for offensive zone start percentage. In 2012 Ruff showed little interest in zone matching, but if you notice the range of values for Quality of Competition you can see that he did place an emphasis on line matching. Ruff relied heavily on Robyn Regehr, and to a lesser extent Andrej Sekera, to check the top lines in the NHL.
Sekera was very successful in his role, but Regehr wasn't great. The biggest criticism I could see for 2012 is that perhaps his reliance on Regehr should have waned as the season progressed, but outside of Mike Weber the Sabres didn't really have a viable alternative. The reliance on Regehr does suggest Ruff's loyalty to veteran players who have entered the trust tree. We'll get back to that later.
2011 stands in stark contrast to 2012. The Sabres had no real checking pair in the mind of Ruff. Sekera ended up doing a very good job in 2012, but in the 2011 season he was used as "one of the guys". Shaone Morrisonn was the Sabres worst regular defenseman that year so perhaps he should have been given easier minutes, but that isn't a glaring criticism. In the grand scheme of things it likely made little difference.
In 2010 the Sabres used Tyler Myers and Henrik Tallinder as a shutdown pairing. Toni Lydman and Chris Butler were clearly given 2nd tier minutes well below the top pairing. Ruff clearly tried to protect Sekera, but not so much as to suggest that he didn't think Sekera was an NHL caliber defenseman.
2009 looks very similar to 2010. The pairing of Lydman and Tallinder got top minutes. Craig Rivet and Jaroslav Spacek saw second tier minutes which were a doppelganger of the level of difficulty the third pair saw. Over this time period Nathan Paetsch is the defenseman who saw regular minutes that Ruff decided to protect the most.
A few things become apparent about how Ruff has managed his defenseman in the recent past. For one, he places little emphasis on starting zone position. His main focus is matchups. If he has a defensive pair he will use them, but if he feels that he doesn't have a strict shutdown pair on his roster he won't bother. The 2011 season is a clear indication of that fact.
Focusing more on the starting zone position of his players is an adjustment Ruff could make that should help him turn this Stars roster into a winner faster. On the other hand, the message delivered by not strictly protecting many players is that he trusts the players on his roster to play an appropriate game. This obviously doesn't work for every player. His strict protecting of Paetsch shows that he is willing to protect someone if he doesn't feel like they can do the job. However, the message is pretty clear that if you are on the roster it is because Ruff expects you to be able to play to his standard without protection. Given the solid performances of the defensemen under him during that time period it's safe to say he has a good eye for evaluating talent.
How this applies to the Stars will be up for debate until player transactions get rolling and into training camp. Given that Ruff has shown the tendency to use a checking pair if one is available, it seems unlikely that Stephane Robidas is going anywhere. It wouldn't surprise me at all to see the Stars pursue a veteran defensive presence to pair with Robidas to form that checking pair. Ron Hainsey, and to a lesser extent, Rob Scuderi come to mind from the free agent market.
Or, the Stars could opt to reunite Robidas with Brenden Dillon as a top pair. Ruff had high praise for Dillon at his introductory press conference, and it wouldn't be surprising to see those two fighting through tough minutes next season. I would expect the rest of the corps to be used interchangeably.
The players who really need to take notice of the coaching change are the young defensemen. Ruff demands defensive responsibility and good decision making. The Stars made horrendous puck decisions at times last year, and the defensemen looked lost defensively for significant chunks of time. If they expect to be on the roster taking regular shifts they have to get it together, lest they barely hang on to a roster spot like Nathan Paetsch.
The defensive deployments could change dramatically between now and August given how active the Stars are expected to be in molding the 2014 club. Defensively at least, we should have a clear picture of what Ruff wants to do.