If you were already over-the-moon excited to see the way the Trail Blazers improved last year during their second full season under Terry Stotts, you have to be even more jazzed about the way this year has begun. Last year's Blazers were a No. 5 playoff seed and a Cinderella story; this year, the Blazers are legitimately one of the very best teams in the NBA.



Doesn't it make you wonder - what's happened, exactly? Very little has changed with the Blazers personnel-wise since the end of last season, so it's hard to pinpoint any one cause for the team's continued improvement. They basically just took last year's team and rolled it back. So what on Earth has driven the Blazers to come out blazing hot in November, putting up a 12-3 month, then follow that up with an even better December at 13-3? What the heck?



There are a few common theories I've heard about the Blazers' improvement this year. They're all decent ones, but none are my very favorite:

Damian Lillard's breakout is the real story here. Dame was an All-Star last year with 20.8 points, 5.6 assists, 3.5 rebounds and 0.8 steals per game in his second season; he's now one-upping himself with averages of 22.2, 6.4, 5.0 and 1.5. Plus his field goal percentage has jumped 3.6 points. He's reached the next level. The 3-point shooting is just lethal this year. Last year the Blazers got 2.7 3-pointers per game from Lillard and 2.5 from Wesley Matthews; this season it's 3.0 from Wes and 2.8 from Dame, plus the addition of Steve Blake gives them another element from beyond the arc. The schedule has been the Blazers' friend - according to basketball-reference, their opponents have been the sixth easiest in the league this season. That 13-3 mark last month was nice, but those 13 wins included cakewalks against the Knicks, Pistons (pre-Josh Smith bombshell), Thunder (with Kevin Durant injured), Sixers and Knicks again. Not too impressive when you look at it that way.



Like I said, all of the above theories are good ones. All of the facts you read here are true. But they're not the most important reason the Blazers are looking like a top NBA team this season. No - this is primarily about something else.



It's the defense, you guys. Really.



Lillard has definitely made some modest improvements, and the overall team shooting has been nice, and the schedule has been friendly. But on the defensive side of the ball, the Blazers have really made hay this season. The difference between 2013-14 and now is real, and it's remarkable.

107.4 - the Blazers' defensive efficiency last season, in points per 100 possessions (tied for 16th best in the NBA)

101.4 - their defensive efficiency this year (second in the league, trailing only Golden State)



That six points per 100 possessions (or, if you prefer the old-fashioned number, they're also allowing 5.8 points fewer per game) is a mammoth difference. It's incredibly rare that a team improves that much defensively in a single season. The only other team in the league that's that much better now than a year ago is Milwaukee, who dropped from 111.8 to 102.7 this season, though that's not really a fair comparison since the Bucks tanked away half their season and finished with the worst record in the league. After that, no one is even close.



The Blazers are way better on defense now than they've been in a long, long time. You might have to go back to the Bill Walton years to find a team like this.



More specifically, what the Blazers are doing is cracking down on opposing outside shooters. All the talk in NBA circles these days is about the changing style of play around the league - teams want offenses that can pace, space and shoot. They want to control the flow of the game, spread the floor, move the ball and find open jumpers - or, as many often put it more succinctly, "play like the Spurs." The Blazers' greatest strength is they're able to game-plan for this style and beat it.

20.2 - the percentage of opposing teams' shots against the Blazers that are 3-pointers (only the Bulls, at 20.0 are lower)

29.2 - the percentage of opposing teams' 3-point shots that they make (worst in the league, and it's really not that close)

31.8 - the percentage of opposing teams' corner 3-pointers that they make (also the NBA's lowest)



Simply put, the Blazers just won't let you get an open jump shot from the perimeter. If you're going to take one, it's going to be forced, it's going to be contested and it's going to be ugly. It'll probably look a little something like this:





What you see above is a pretty typical example of how the Blazers defend against teams who try to spread them out and shoot. There are no gimmicky tricks here, no double-teaming or trapping or anything of the sort - the Blazers are just quick and scrappy and rip through screens to stay with their man. Watch what happens as Ryan Anderson tries to pin down Lillard with a screen after his dribble handoff to Austin Rivers - Lillard quickly dodges the screen, he stays with Rivers and LaMarcus Aldridge stays all over Anderson. No way he's shooting. Then the Pelicans swing it to the right side, where Jrue Holiday attempts to get off a 3 using a screen from Anthony Davis. Blake rips right through it, stays with Holiday and gets him to miss a tough contested shot.



By and large, this is how the Blazers have defended all year long. They're blessed with the right personnel for it - their rotation, one through nine when healthy, is made up of guys who are quick and long-armed, meaning they're excellent at beating screeners and contesting shots. They also all play hard - and unselfishly together. If one guy messes up, there's another Blazer defender willing to cover for him.



This is the next step in the team's development. It's easy enough to be a playoff team in the West if you have five guys on the roster who are skilled at running, gunning and hitting shots. That's enough, if you do it at a high level, to win you 50 games. It won the Blazers a playoff round last May, even. But as they learned when they ran into that San Antonio brick wall in round two, you eventually reach a point where a blitzkrieg offense alone is not enough. To beat the best of the best, you need a well-rounded game plan. Thanks to their defensive improvement, Portland now has one.



If the Blazers' rock-solid defense keeps up, there's a chance this team is for real - that this 28-8 start and second-place standing in the West is no fluke. As long as the effort remains there, they've got a good shot.