Think of the man who wants to run his first marathon. He maps out a specific training schedule, one that will cover several months before the actual race. His regimen begins with short runs and builds from there. The idea is to strengthen his lungs and endurance over a period of time. The idea is to reach his ultimate level of fitness.

This is how Casey Jacobsen has approached his jump shot, only the months are years and there is no telling what his ultimate level might be on a basketball court.

There is no telling where his range will stop.

Locker room, maybe?

Parking lot?

"I've worked on shooting deeper since my sophomore year in high school," said Jacobsen. "I was 15 then and really had confidence from one foot beyond the 3-point line. I'm 20 now, and feel very comfortable six to seven feet beyond the line.

	When he squares up to the basket, Casey Jacobsen can drain jumpers from anywhere on the court.

"A lot of it happened because people wouldn't let me shoot an open 3 in high school. They took them away. So, to get some space, I backed up a little."

He hasn't stopped since.

The nation's most dangerous shooter is a 6-foot-6 junior at Stanford who believes a jumper is made in the gym and not the weight room, who doesn't pay attention to makes and misses during warmups, who has a penchant for analyzing the texture of a ball or the tightness of a rim before tipoff. It's uncanny, really. He is that precise when it comes to shooting. He is that specific about detail.

It's not about shot attempts any more. It used to be, when he was younger, when he just wanted to improve his form, when he grabbed a ball and spent a Saturday afternoon heaving up 500 or so jumpers. It's about makes now. All makes. Jacobsen won't leave the gym, won't stop a drill, won't accept success until he has drilled a certain number of shots.

"In that way, Casey is a lot like Tracy Murray, who I coached at UCLA," says Stanford assistant Tony Fuller. "Both went to the same high school (Glendora) and both can't go to sleep at night if anything is bothering them about their shot. They'll work for hours on just one part of it.

"Casey is a tremendous worker. He is a great player who does not walk around acting as though he is blessed and gifted. And yet he has proven he is very special by working so hard on his shot."

The shot last season produced a 18.1 scoring average, 47-percent acuracy from 3-point range and first-team All-America honors. And yet the jumper is still a work in progress, still leaves Jacobsen exhausted on most days.

The legs and arms dangle, the sweat drips onto hardwood.

"I lift weights, but I've always felt the only thing that matters is what you do on the court," said Jacobsen. "Shooters have to shoot. I can improve my bench press or squat numbers, but my confidence comes from practice and shooting drills. Confidence doesn't come in the weight room. No, no, no. The thing that gives me confidence to take a 26-footer in the game is that I have made so many in practice."

It's been this way since he arrived two seasons ago as a shoot-first, answer questions about the shot later freshman. Jacobsen set a freshman school record for 3-point attempts (170), but also set the freshman standard in made treys (74), while his 43.5-percent clip is third-best by a frosh. Last season, his 84 3-pointers passed Dion Cross ('92-93) for single-season honors.

Sometimes, he watches film of those games. Lots of it. And when No. 23 flashes on the screen and Jacobsen sees himself catch a pass in rhythm and square his shoulders, he sees ball hitting net time and again. But when he sees a body off balance, he sees ball hitting rim.

	“	I lift weights, but I've always felt the only thing that matters is what you do on the court. Shooters have to shoot. I can improve my bench press or squat numbers, but my confidence comes from practice and shooting drills. Confidence doesn't come in the weight room. No, no, no. The thing that gives me confidence to take a 26-footer in the game is that I have made so many in practice. ”
		— Casey Jacobsen, Stanford junior forward

Range? It's just a number to him any more. Twenty-six feet, 27, 28 ... it's just another spot on the court to own, just another mile or two the beginning marathoner must reach. You get the idea fun for Jacobsen is not extending his shooting range, but the long process it takes to do so.

There are few arenas, few backgrounds, few opposing crowds that affect his release. Warmups, again, mean nothing to him. Make 20 straight, miss 20 straight, whatever. His goal: Be a gamer. Make them when they count.

"His confidence has grown each year," said Stanford coach Mike Montgomery. "Casey works on his game as much as anyone we have, so it becomes easier to allow him more freedom in his decisions."

It is an interesting relationship the head coach and star player have. Montgomery has allowed Jacobsen more independence than others in Stanford's controlled offense by adapting a style more towards emphasizing backcourt talent.

There have been times, of course, when the ball went up from closer to half-court than the basket and the head coach rolled his eyes skyward. The kid had tried extending his range again, taking the term "downtown" a bit too literal for Montgomery's liking.

"We don't really have a problem with that now," said Fuller. "Now, we just tell Casey 'Shoot!'"

Jacobsen, however, wants to be known for more than just the player with the country's best jumpshot, and yet openly accepts it is how most define him. He embraces it to a point, even. Jacobsen figures he has put in the hours, shot the shots, iced the muscles and earned the label.

He can't tell you where that fine line is yet, where his range goes from deadly to semi-accurate to what-in-the-world-were-you-thinking?

He just knows how to flirt with it, is all.

"I have proved to my coaches and teammates that I can make the shots I take," said Jacobsen. "I've tried not taking it too far, but I also want to push the limits and become the best player I can be. Until I think it's too far out, I'm going to continue trying to improve my range. If it's too far, I'm sure (Montgomery) will call me into his office."

Has that happened yet?

"Yeah," said Jacobsen. "But never about my shooting."

No wonder.

Ed Graney of the San Diego Union-Tribune is a regular contributor to ESPN.com. He can be reached at ed.graney@uniontrib.com.