Figuring out the most improved player in the NBA is a lot like picking the most valuable player. The criterion is always the problem.

Is it the guy who comes out of nowhere with good stats?

Is it a good player who becomes a better player, or a good player who becomes great to help his team win?

Is it a disappointing player who finally puts it together?

You can make a case for all of the above as we give you the five most improved players and settle on one. Our top candidates are Orlando’s Hedo Turkoglu and Dwight Howard, Rajon Rondo from the Celtics, Portland’s LaMarcus Aldridge and Jose Calderon in Toronto.

Right out of the blocks, we eliminated a top candidate – the Lakers’ Andrew Bynum because he played in only 35 games due to a knee injury and has been out since Jan. 13. It’s a shame because Bynum went from averaging 7.8 points, 5.9 rebounds and 1.6 blocks as an iffy center a year ago to 18 double-doubles this season – averaging 13.2 points, 10.2 rebounds and 2.1 blocks with a major impact on the Lakers.

Another decent contender who would be tough to vote for would be last year’s winner, Monta Ellis, even though he has improved. He went from being an immature guard with skills right out of high school two years ago to an impact player last season while averaging 16.2 points, 4.1 assists and 1.7 steals, allowing the Warriors to trade Jason Richardson for the draft rights to North Carolina’s talented 6-10 Brendan Wright. Ellis has responded with flashes of stardom, at 19.8 points, shooting 53.3 percent from the field, and became one of just nine players in history to shoot better than 60 percent from the field in a month (February). But we know about him now and he hasn’t improved so much from last year that he can become the first ever to win the award in consecutive years.

So is including Howard but not Ellis a double-standard? No, because Howard has gone from being star quality to a superstar – leading the Magic to the third-best record in the East. He’s the key figure in nearly every game, leading the NBA with 63 double-doubles and in rebounding at 14.5, and has increased his scoring average from 17.6 to 21.2 while also leading the league in free-throw attempts. He has become the most dominant big man in the game. But because he was an All-Star, he’s fifth in the countdown.

Aldridge had nine consecutive 20-plus games for the Blazers until spraining his ankle Monday night at Seattle. At 6-11, 240, he was the second overall pick of the 2006 draft, and to some that eliminates him right there because of expectations. I don’t buy that one. Part of a draft day deal from Chicago, he blew hot and cold as a rookie, averaging just 9.0 points and 5.0 rebounds in Zach Randolph’s shadow. But when Randolph was unloaded and 2007 top pick Greg Oden went down with a knee injury, Aldridge began to blossom and has averaged 17.7 points, 7.3 rebounds and 1.3 blocks as a power forward. He’ll be even better next year with Oden and along with Brandon Roy has everything to do with why the Blazers have been one of the surprise teams in the league.

Third is Calderon, a point guard who very quietly kept the Raptors flowing in the wake of another serious spinal injury to starting playmaker T.J. Ford, and the knee problems that have had All-Star Chris Bosh in and out of the lineup. He’s raised his average from 8.7 points to 12.2, and improved his field-goal (53.2 percent), 3-point (45.2) and free-throw shooting (91.9). He’s also up to 8.0 assists a game while leading the league in assist-to-turnover ratio. He would have been higher, but his effectiveness has dropped off since Ford and Bosh returned. The team is struggling with its chemistry. but it certainly has nothing to do with Calderon, who has kept the chemistry intact for the bulk of the season. He’ll be a free agent at the end of the season and will create a lot of action because he’ll make somebody better.

Second in the countdown is Rondo, the feisty 22-year-old point guard that Danny Ainge refused to part with in his offseason reconstruction. It has paid off remarkably with Rondo setting the tone for the defensive orientation of coach Doc Rivers with relentless pressure on the ball. He’s also raised all of his numbers to 10.6 points, 4.1 rebounds, 5.0 assists, 1.7 steals and improved his shooting from 41.8 to 47.8 percent. The only reason he didn’t win is because it helps him immeasurably to have veterans Kevin Garnett, Ray Allen and Paul Pierce around him. Nonetheless, the 6-1 Rondo has responded superbly in just his second season and has a lot to do with Boston’s record-breaking success.

So that hands this year’s award to Turkoglu, the versatile 6-10, 225-pound native of Istanbul. With great expectations as a rookie in Sacramento in 2000, there were thoughts he would play point guard like Magic Johnson, or score at will, and things never really panned out in his three seasons there. He was part of a three-way deal between the Kings, Spurs and Pacers, sending him to San Antonio for one mediocre season and he signed as with Orlando as a free agent in 2004. That’s when things gradually began to change. His numbers and impact went up, but nothing like this season. Turkoglu, Howard and Rashard Lewis consistently put up the best numbers in the game.

However, Turkoglu has been the X-factor all season and should have been an All-Star. He tied a franchise record with two triple-doubles and has had eight double-doubles; beat the Celtics with a 3-pointer at the buzzer in a huge win, and raised his numbers to career-highs with 19.6 points, 5.9 rebounds, 4.9 assists, 83.4 percent on free throws, 40.7 from 3-point range and 45.3 overall. He has become a star for the Magic, the man with the ball in the clutch, and has responded.

And that’s why he is our most improved player for 2008.