Even after injuries wreaked a catastrophic toll on the Knicks, the team still look substantially better than last year’s in most regards. The offense is improved, the young players are improving, and there is a greater sense of structure among the team members.

Yet when it comes to defense, the current Knicks are surprisingly similar to last year’s model. When measured via Defensive Efficiency, points allowed per 100 possessions, this year’s Knicks are 25th in the league; last year they were 26th. When measured via the four factors, a system devised by Dean Oliver in his book “Basketball on Paper,” you might forget that there had been a coaching change.

Oliver’s four factors are opponent’s Effective Field Goal Percentage allowed (eFG% is a metric that factors in the different risk/reward ratio for three pointers), percentage of opponents’ possessions that result in turnovers, percentage of available defensive rebounds grabbed, and number of free throws allowed per 100 shot attempts. By examining them we can get a clearer picture of what the Knicks can do to improve.

Last season the Knicks allowed opponents an eFG% of 51.1%, 26th in the league. This season they’re allowing 50.4%, 23rd on the circuit. Last season, the Knicks forced turnovers on only 14.9% of the opponents’ possessions, which ranked 22nd. This season that number is 15.1, dead last in the NBA. Last season’s unit (if you could call them that) cleaned the glass on 72.8% of the opponents’ misses, 13th in the league; this year’s bunch is grabbing 73.7% which places them 12th. Last, free throws allowed are the only area where it is clear that this year’s team is truly different. Larry Brown’s Knicks allowed opponents 29.4 free throws per 100 shot attempts, which ranked 28th among the 30 teams. The Isiah Thomas-coached Knicks have improved to 24.4 or 16th.

Were it not for three throws allowed, you might conclude, absent any local hoops news from last summer, that the same guy is still coaching the Knicks. The conventional wisdom is that defense can be taught, but these figures suggest that maybe it really is a product of nature and not nurture.

The urgency for the Knicks to improve on D goes much deeper than adhering to the adage that defense wins championships. The Knicks have many hurdles to clear before the word “championship” genuinely belongs in same sentence with their near-term aspirations. However, the Knicks greatest potential for improvement is on D. The team has improved this season from a horrid 25th in the league in Offensive Efficiency to a mediocre 18th. With a better run of health and some improvement from the young players the team could move up a few spots, but with a defense in the bottom sixth of the league, the Knicks can’t serious think about moving into the elite, not even the inferior Eastern Conference elite.

But what can be done? The team is capped out (even with $60 million in salary coming off the books this summer). The roster is still full of players with duplicative skills. The solutions, short of some stud slipping to the Knicks at pick no. 24 in the first round (or wherever the Bulls pick lands them), aren’t easy to find.

The improvement in free throws allowed is a solid indication that the Knicks are forcing teams to take more jump shots rather than play the matador defense and allow them to drive the lane. Some of that improvement owes to firstround pick Renaldo Balkman. His tenacious defense on perimeter players has helped enormously. One key to improving the defense will be getting him and Jared Jeffries, the other solid perimeter defender, more burn.

A team can build a solid defense on the basis of the perimeter stops — just look at the Nets. Save for Dikembe Mutombo’s brief tenure, they have lacked a dominant post defender until this season, yet New Jersey during the Jason Kidd era has always ranked near the top in most defensive metrics. However, the Knicks’ second priority will have to be developing the newest member of the team, power forward/center Randolph Morris. Morris was a scorer at Kentucky but his offensive skills (16.1 ppg on 59.2% shooting in his last NCAA season) may have obscured some emerging defensive game. Morris’s blocked shots per game doubled to 2.1 a game this season (about the same per-minute average as the entire Knicks team). He’s also a good rebounder. In other words on defense, he’s everything Eddy Curry isn’t. The Knicks blocked only 3.2 shots a game this season, second worst in the NBA. Without a better interior defense, their team defense will still stink.

Many if not most observers expect the Knicks to buy out the contract of guard Steve Francis, and there is good reason for the move since Francis never really found a role with the team and his minutes could go to a younger developing player. However, the Knicks shouldn’t stop there. They should also buy out the contract of reserve center Jerome James. Any burn he gets is taking away minutes from Morris.

I doubt that even in the best case scenario the Knicks can join the likes of San Antonio, Chicago, or Houston among the elite defensive teams in the league, but they can improve to the middle of the pack, and a young team with an emerging offense and a decent defense would easily be the best squad to wear the orange and blue at the Garden this decade.

mjohnnson@nysun.com