PDO: Essentially a measure of luck. SH% + SV%. Almost always regresses to 100 since every SOG results in either a save or a goal. Too high and they're overachieving, too low and they're underachieving.
2005-06: Wow did this team overachieve. Look at it compared to 2009-2012 and think of where each team finished. They were lucky, and that's okay, but they also built a speedy team to take advantage of the "new" rules, especially the ridiculous amount of special teams gameplay.
Playoffs: "Luck" caught up a bit and they struggled at times for it. Again, special teams were really important.
2006-07: This is kind of a massive jump in FF% while seeing an equally large decline in PDO. Any theories? It'd kinda point to them bringing in a whole bunch of volume shooting grinders like Nathan Gerbe, but it was pretty much the same team.
2007-08: "Underachieved", ever so slightly. Would have been very interesting to see this team in the playoffs had they beaten Florida.
2008-09: Basically this is the team we've expected them to be whenever optimism floats around. Not super talented, so their regressed PDO is probably going to be a bit lower than 100, but a tough team to play against.
Playoffs: Ran into some tough opponents then ran cold.
2009-10: Sucked and earned it.
2010-11: They probably should have been even worse than they were. Jeff Skinner probably single handily resulted in several points in the standings.
2011-12: Sucked and earned it.
2012-13: Like with the playoffs, this is a smaller sample size, so it's far less concrete than the fuller seasons, but they were more the first half team than the second half. The goaltender injuries killed them, and IIRC everyone aside from Staal, Semin, and Tlusty shot at a pretty low %.
2013-14: Probably deserved a few more points in the standings, but not a playoff team.
2014-15: Stop changing the ****ing lines every 10 shifts and maybe that near league-worst PDO will rise and they'll finish chances. There's a lot of reason to be optimistic, but this team is kinda filled with some of the aforementioned Gerbes. At worst, we should be looking at a bubble team.