It is helpful, obviously, for the golfer to know how far he hits each club in his bag. For those who don't know or aren't sure and want to find out, Ernest Sports has introduced the ES12 Digital Golf Assistant.

It employs Doppler radar to measure ball speed, then based on what club you're hitting calculates the distance that then is relayed via Bluetooth instantly to a smart phone or audibly to a hands-free device. The mobile app will log practice sessions (up to 2,000 shots, in fact) for later analysis.

The question, of course, is accuracy, given that it does not consider ball spin, angle of attack or the variations in loft that might occur between equipment manufacturers' respective irons. "It's proven pretty accurate," said Will Moore, the engineer who designed the device. "There are shots like a thin shot or a 30-yard slice that would be off, but it's pretty accurate on better strikes."

The company provides a spreadsheet comparing distances recorded by the ES12, a laser rangefinder, and a launch monitor.

The app comes with a few other features, including a digital scorecard and stat keeper. It also is capable of showing frame-by-frame video of your swing taken by a smart phone for the purpose of swing analysis.

The ES12 retails for $249.

-- John Strege

Go to any PGA Tour or LPGA event and you'll see players who aren't being paid to do so using a variety of putting aids on the practice green. Their unofficial seal of approval is one way to cut through the clutter in the training aid category.

Among those that has been in use at tour events, including the Masters, in recent months is the Straight Trax, a new introduction from MVP Sports, a company whose core business has been alignment rods.

The Straight Trax was developed by Dwight Hansen of MVP Sport, who saw a rudimentary device in use at the PGA Tour's Children's Miracle Network Hospitals Classic a few years ago. "A couple of the players had a contraption with an alignment rod and acrylic pieces," Hansen said. Hansen decided to devise one that was better and more versatile and to market it.

The principal benefit of the Straight Trax is to help promote a straight back, straight through putting stroke. Another is stroke height, an area on which instructors are focusing more, Hansen said. "If you take it back inside you're going to hit a rail. If you lift the putter you're going to hit a rail. The way we designed it was to make it intuitive, where you're getting physical feedback."

Its simplicity and affordability ($30) make it an attractive product for anybody, from the tour player to the recreational player. "It's fun to get a product in play with the best players in the world," Hansen said, "but we wanted to make something that really works for anybody. "

The product comes with five rods and two end pieces and breaks down to fit in a side pocket of a golf bag.

-- John Strege

There are probably thousands of training aids available, some of them even useful. One such device might be the CentreCup, a contraption designed to build muscle memory into your stroke.

It came to our attention through Don Hurter, the head pro at Castle Pines Golf Club in Castle Rock, Colo. Hurter is a former U.S. Junior Amateur champion who has been ranked on Golf Digest's list of America's 50 Best Teachers.

"I found this at the PGA Merchandise Show [in January]," he said of the CentreCup. "It's a putting device that you get into and it shows you what your stroke is or should be. It doesn't need any supervision. Once you put it on and stroke it, it automatically puts you into the correct postiion.

"It looked intriguing. I've been in other machines that never felt quite right. This one takes your hands out of the stroke...and makes sure your shoulders are square."

Hurter ordered one and is shown above demonstrating it. CentreCup was developed by a European teaching pro, Ian Melville. He is a proponent of the straight-back, straight-through method of putting, and the CentreCup was designed to replicate that movement.
He advises using it 10 minutes a day to build muscle memory."

Incidentally, there is a CentreCup Pro available, that can be inclined to accommodate the inside-to-square-to-inside stroke that many tour players use.

The CentreCup is not cheap and no doubt not for everyone. It sells for about $1,100 and can be purchased here.

-- John Strege

When the brands Apple and Microsoft are invoked, it tends to get one's attention, as it has in the case of GolfSense, a 3D swing analysis device that attaches to a golfer's glove and provides instant feedback to an iPhone or iPad.

GolfSense is the brainchild of Robin Han, who once worked on software and sensors for Microsoft Research Asia and has a PhD in aeronautics and astronautics from Bejing University. The device, which retails for $129.99, is now available at all Apple stores in the U.S. and Canada.

The information it provides includes clubhead speed, estimated carry distance, swing path, swing plane, tempo and even tips on how to fix what might be wrong with your swing.

"We've been working with a couple different professionals, one of them Brett Taylor in the Sacramento area," said Jason Fass, CEO of the company. "We view our role in this relationship as providing you with the data and high-level tips: 'We notice this, you should look at the following things.'"

The device weighs only 17 grams and attaches to the back of the golf glove. It is equipped with four motion sensors that relay information via a bluetooth connection to an iPhone or iPad that has the free app installed on it.

-- John Strege

Simplicity for the user is always welcome in training aids, and a San Diego-based inventor, Voz Kumar, has developed one that could not be easier to use.

Kumar calls it the VozTee, designed to provide instant feedback on the path your club is traveling at impact. It features a Vector Analysis Movement Pivot, basically a tee on a swivel that ends up pointing in the direction your clubhead was traveling.

"I'm a golfer, but also an engineer," Kumar said. "A lot of it was me struggling with what's actually happening at the point of impact. For a lot of high and medium handicappers, everything is happening so fast it's hard to gauge what's happening in that instant."

Its simplicity of use notwithstanding, there is technology built into the device (hence it's price, $40). For instance, the top part of the VozTee snaps into place after impact, thus providing immediate and precise feedback on the clubhead path, whether it's moving from outside in or inside out and to what degree.

"I've got it to a point where I've had pros test it, and they've told me it's pretty accurate," he said. Among them was Michael Major, a professional at Torrey Pines Golf Course.

"It lets the golfer know what his clubhead path is doing," Major said. "You hit that thing and it's on that swivel, and the student's going to get feedback."

It's a clever little device that can help those who are hitting crooked shots figure out why.

-- John Strege

Mark Immelman, brother of former Masters champion Trevor Immelman and one of Golf Digest's top 20 teachers under 40 in 2009 (he's now 41), embraces simplicity in his teaching.

"As a golf instructor, what gets me about a lot of them is that they use training aids that are intricate or difficult to use," Immelman said. "I base my entire teaching philosophy on the more simply you can apply these things the better. This was right up my alley."

He was talking about the PutterMaster, a simple training aid that attaches to your own putter and won't allow your wrists to break down during the stroke. Immelman is the director of product development for PutterMaster, which is based in Columbus, Ga.

"The whole premise of this thing is stability in the wrists," Immelman said. "It forces correct alignment of the forearms as well, which is crucial to success. The simplicity of this was very intriguing to me, and it touches on an area of the game that can have a huge effect on your score. If you putt well, your scoring is going to improve."

The PutterMaster sells for $29.99 and can be purchased here.

It is a common drill, one often used by Vijay Singh, who places the ends of a towel in his armpits to "stay connected," to help the arms and upper body work in concert. Rick Gonzales, a mortgage broker in Stockton, Calif., saw an amateur golfer using the drill on the range one day.

"That's what spurred the idea," Gonzales said. The idea became the Core Swing, a polo shirt designed to do what the towel does. It features elastic that tightens around the bicep of each arm, securing the arms in the proper position.

"I'm just a 15-handicapper," Gonzales said. "I thought, 'there's got to be a better way.' My wife always teases me. I'm the guy who always buys the newest and best training aid, looking for a shortcup to a better golf game. I figured there's got to be a way to design a polo shirt that does what the towel does, but you won't be embarrassed [tucking a towel in the armpits] on the range.

"The main purpose is keeping the core, your chest, and rotating that and letting the arms come along for the ride. It allows you to make the proper turn."

The Core Swing is available in white or navy blue and sells for $89.99.

-- John Strege

A husband attempting to teach his wife golf is not necessarily a good idea, but a good idea might have emerged from Chip Beck's efforts to assist his wife Karen with her golf.

"After 22 years of marriage, I said, 'Chip, I've been invited to play in a member guest. I don't know how to play. Can you show me how to play?'" she said at the recent PGA Expo in Las Vegas.

Chip, a winner of four PGA Tour events and now a Champions Tour member, gave her a lesson.

"I was hitting it great on the range," she said. "Then he went out of town for a few weeks. We ended up winning the member-guest. When he came back I said, 'there's only one problem. My thumb hurts.' He said, 'show me your grip.'"

Karen gripped a club for him. "What are you doing?" Beck said to her. She explained that her caddie had showed her the grip.

"Don't listen to the caddie, listen to me," he replied.

"I had forgotten what he had told me about the grip because it was so complicated," she said.

The upshot is Grip Guides, a training aid they developed together to help golfers "grip it like a pro."

It adhesively attaches to the grip of any golf club and features three lines -- in the 11, 12 and 1 o'clock positions, as well as a guide on where to place your hands. It uses the Vardon grip as its model.

In addition, the aid features interactive thermochromic ink that changes color. Thermochromic ink on Coors beer cans and botles features cold activation to demonstrate that the beer is cold. On Grip Guides, it uses warm activation. If the colors don't change while gripping the club, you're gripping it wrong.

"I wanted something on my grip that can remind me, to make it easy," Karen said. "My method is KISS -- Keep It Simple Silly."

Grip Guides was introduced at the PGA Expo and will go on sale later this month. Ten percent of the proceeds will benefit the renowned Evans Scholarship Foundation.

-- John Strege

Golf, a wise man once said, is played on a five-inch course -- the distance between the ears.

The wise man was Bobby Jones, who had to overcome a bad temper and a loss of focus before his talent was allowed to flourish. This speaks to the importance of the mental side of the game that many professional golfers now address by employing sports psychologists.

But what about the rest of us?

"At the PGA Center for Learning and Performance," PGA professional Joe Hallett said, "we had seen every training aid known to man, the neatest stuff. But there was this wide open area of the mental side of the game."

Enter Brain Center International, a scientific society specializing in the field of neuroscience. Based in Quebec City, Canada, BCI has developed a brain training program for golfers, Pro Mental Coach, that has been embraced by the PGA Center for Learning and Performance at PGA Village in Port St. Lucie, Fla.

Pro Mental Coach provides a personalized training program that is done in the comfort of your home. If stress management is a weakness and focus a strength, the program will provide more brain exercises for the former and fewer for the latter.

"These guys came with something that's doable, fun, short-time segment, chunk learning, whatever you want to call it," said Hallett, who counts LPGA star Stacy Lewis among his students. "It's interactive. It's always changing."

It begins with an assessment test that includes questions about your latest rounds of golf from which a personalized mental-game profile is developed and a mental coaching program is recommended. It features what BCI calls "exergames" that replicate on-course situations that heighten stress. These exergames exercise different areas of the brain that are said to help in these areas, among others: mental endurance, focus, stress management, how to get in a zone, and how to recover mentally from a bad shot.

The time commitment, BCI said, is 20 minutes, three times a week. The cost of the program is $139.95.

-- John Strege

Alignment sticks are ubiquitous on professional tours and they're often seen protruding from golf bags. Golf Alignment has developed one that it calls Sure Stick that easily folds into four sections of equal length, allowing it to be stowed out of sight in a golf bag pocket.

The four sections are held together with elastic shock string. When they're extended end to end, it becomes a rigid alignment stick that measures 47 inches.

Shown here is the Sure Stick at its full length:

Here is the Sure Stick when folded up and ready for storage:

The Sure Stick, made of fiberglass, has an MSRP of $29.95 for a set of two.

-- John Strege