"It was so overwhelming [at first] that I thought it would be worthless," he said. "You look up, and the ball comes in at 140 mph, and you can barely see it."
Hafner thought to himself, "I'm getting nothing out of this."
But the longer he stayed in the cage, the more he grew to like the vision drills. He soon started to see more than a 140-mph blur. Once he let someone ratchet down the machine's speed, Hafner could read the numbers. The closer the speed of the tennis balls got to the speed of a Justin Verlander fastball the better Hafner saw everything.
"If I can watch a tennis ball come in at 130 mph and get used to seeing that speed, a 90-to-94 mph fastball will look slow," he said. "I'll be able to see the spin on it a little bit better.
The people at the National Baseball & Softball Academy in Wheeling, Ill., believe that the point of their patented vision system is helping hitters see the baseball better or, more precisely, to focus on it better.
They say the human eye, as with other muscles in the body, has the ability to become stronger, quicker and more productive.
Fact or fiction?
Dr. Mike Ehrenhaus, an ophthalmologist, isn't comfortable with using the phrase "seeing the ball better" or with saying that the vision system can strengthen a player's eye muscles.
He flat-out disputes any claim that I trac will improve a player's vision.
"The point is you have to have good vision to pick up the ball in the first place," said Dr. Ehrenhaus, chief of refractive and cornea surgery at Long Island College Hospital in Brooklyn, N.Y. "When you train enough and you pay attention to the ball more, that, of course, gives you the ability to have a better effective swing."
The vision training system seems to have value, he said, in improving a player's focus and his perception, which were behind the concept in the first place.
Some ophthalmologists, however, don't see eye training doing even that much.
Dr. Harry Engel, chairman of ophthalmology at Montefiore Medical Central in the Bronx, N.Y., said no scientific evidence exists that a training system can help the eye focus better.
"There's a practice factor," Dr. Engel said. "If he practices against good pitching, he might be able to hit good pitching more easily. But as to the idea that just watching balls go by quickly will make your reaction time faster and make you able to hit the ball more easily, there's no evidence that the visual system can be augmented that way."
Dr. Engel said he discussed I trac with a colleague, Dr. Edward O'Malley, a respected ophthalmologist who practices in Grosse Pointe Woods, Mich.
In an e-mail, Dr. O'Malley wrote Dr. Engel: "Reading numbers may train him to read numbers faster and with more accuracy, but it is really like using ultrasound to keep the crows off your corn; why not use a scarecrow?
"At all levels, the placebo effect in sports is great, and confidence at the plate is paramount. If a guy can read numbers off balls he might have more confidence and that might be translatable into RBIs.
"For my money, I would take more batting practice against better pitching."
Is it just hi-tech BP?
Is I trac simply a form of hi-tech batting practice?
That seems a good way to look at the machine, because one of baseball's maxims has always been, "See the ball, hit the ball." But how can a player hit what he can't focus on it?
"The eyes are the first thing you need to work on," said Jason Stein, a certified vision trainer, a former Minor League umpire and the son of former Major Leaguer Bill Stein. "People just don't realize it. I mean, you can have the best swing in the world, but try to hit the ball with your eyes closed."
Stein's point is one that several Major League organizations share. The Indians, the team Stein is assigned to work with, have used the vision training system, once called "Conditioned Ocular Enhancement Vision Training," for about five years.
When the organization was approached about the vision system, it agreed to give it a tryout, said assistant general manager Chris Antonetti. The Indians let a handful of players test the machine, and Antonetti said they gave the vision system high marks.
Their reaction led the organization to contract with the baseball academy to make the vision system available to players at the Major League and Minor League levels.
Antonetti believes that the vision system, a roughly $90,000 per-season investment, is just another developmental tool the Indians can use to help a player draw the maximum out of his talent.
"I think this is one opportunity that we looked at that seemed to have some positive results," he said.
I trac isn't the only training system available to ballplayers. The old "Iron Mike" pitching machine and the video-imagining "Pro Batter" remain fixtures in batting cages across the country, and soft-toss drills and hitting off tees do have value as well. But none focuses specifically on training the eyes to track the ball better, which the I trac seems to do.
"You can go to any Little League field ... and what you're going to hear more than anything is: 'Hey, Little Johnny, keep your eye on the ball,' But nobody works at it."
-- I trac's Eric Maleski
"It's seeing the baseball and focusing on seeing the baseball, so it can't be a detrimental thing," said Derek Shelton, hitting coach for the Indians. "It's just a matter of how they use it."
Stein said most of his teaching is done in the first few sessions as he introduces the vision machine to players. He tells them what they can accomplish through vision training. They don't need many sessions to decide whether they like the vision drills and want to fit those drills into their daily routine, he said.
"When used properly, the vision system helps players from the Major Leagues down to the Little Leagues follow the baseball's path to point of contact", said Eric Maleski, I trac's director of Major League vision training.
"You can go to any Little League field in America, and probably around the world, and what you're going to hear more than anything is: 'Hey, Little Johnny, keep your eye on the ball,' " Maleski said. "But nobody works at it."
Who it helps
The vision system works best on younger ballplayers, Maleski said. Their vision tends to be sharper than the vision of older players.
Like Stein, Maleski made it clear that I trac may improve a person's concentration on the ball. The reality is that neither a Major Leaguer nor a Little Leaguer can track the baseball if he's not concentrating on it. Players who like I trac say it helps in that regard, which is why Antonetti and Shelton see value in the technology.
"As the hitting coach, we're going to back guys doing things that they think will help," Shelton said. "Vision is such a new technology to the game in terms of importance. We have guys who support it, so we're going to use it."
Yet Shelton said the organization doesn't force players to use the system. The philosophy, Antonetti said, is to introduce vision training to players at the Major and Minor League levels during Spring Training.
Other organizations, like the Yankees, Diamondbacks, Mets, Cubs, Royals and Tigers, have used I trac either during Spring Training or during a full season.
It's outta here
The Tigers used the I trac system throughout the 2006 season, but when Don Slaught left as their hitting coach, Lloyd McClendon replaced Slaught and decided to discard the vision technology.
"I didn't like it," McClendon said. "Some of the greatest hitters of all times did it the old-fashioned way: good, solid work habits, particularly in BP."
He dismissed I trac as a gimmick, though McClendon didn't want anybody to view him as an old man who had no use for cutting-edge technology. He wondered aloud, however, how a machine like I trac can help somebody hit a hard, biting slider. He also wondered why no Tiger asked him about bringing it back.
"I'm always skeptical of people trying to re-invent the wheel, because hitting is pretty simple," he said. "See the ball, hit the ball."
But Hafner said that's how the system helps people who use it. They come away from the drills with sharper concentration and a steadier head for following the ball's flight. He understands, though, why someone like McClendon might be wary of I trac.
"Hitting is a weird thing," Hafner said. "Everybody has their own rituals that they do. Hitting is all about feel and what makes you feel comfortable at the plate."
What makes him feel comfortable, he said, is 10 minutes of vision training -- his fitness routine for the eyes. He likes being able to concentrate on pitches coming his way at 130 mph.
"So if I can get my eyes use to seeing 130 [mph] or whatever, you go down to 100 mph and you see the ball great," Hafner said.
See the ball, hit the ball
The concept behind I trac is to condition the eyes and help them focus better to improve the results on the field.
"Of course," Dr. Ehrenhaus said, "you're more effective when you're not thinking about other things, when you're focusing on what you have to do and not worrying about what's going on around you."
Are such results necessarily measurably in baseball numbers?
Maybe at some point, but not now. Stein does know that ballplayers like Hafner, Carlos Beltran, Jose Reyes, Casey Blake and Trot Nixon rave about I trac.
"When we talk hitting, we talk about tracking the ball deep, letting the ball get to you and having your head down on contact," Stein said. "This system helps reinforce that -- over and over and over."
Perhaps that's the real value of I trac, Dr. Engel said. Reinforced behavior breeds confidence, and confidence isn't a bad thing for athletes.
"That's what their machine may be doing," he said. "If they look at balls that are going very fast and try to hit them, they may have more confidence in trying to hit pitched balls."