The story behind these revolutionary irons actually began with the development of our Great Big Bertha Titanium Drivers. Super-strong, super-light titanium had remarkable benefits in making a forgiving, easyto-hit driver. But for irons, developing titanium clubheads was a new challenge. After making prototype after prototype, we discovered that the optimal swing weight of an iron made of 100% titaniurn simply made the clubhead too big, in our judgement. Unlike drivers, irons must also be equally effective from a variety of lies and conditions from both fairway and rough. At the proper weight, the extra-large size of a 100% titanium iron caused it to twist and drag when hit from the rough. In addition, the center of gravity was too high. As a result, they failed to hit the ball solidly, except when the ball was teed up. How to retain the benefits of a titanium iron while making the clubhead the proper size was the problem. The solution was the addition of a specially designed tungsten inset placed in the strategically perfect position.
By incorporating the proven design features of our Big Bertha Irons into a slightly larger titanium clubhead combined with a tungsten inset, we made three things happen:

- We created the ideal size in irons for greater confidence, more forgiveness and even greater ease of use, especially out of the rough.

- We positioned the sweet spot in the optimum location for getting iron shots airborne more easily than ever before.

- We achieved the most solid feel ever produced in irons.
The tungsten inset is the key. Although it represents only 15% of the volume of the overall clubhead, tungsten is such a dense material that this same inset accounts for 40% of the clubhead's total weight. By positioning the inset low and deep in the clubhead we found the ideal center-of-gravity location. That makes our Great Big Bertha Tungsten#Titanium Irons easier to hit, more solid in feel and more accurate for distance control and directional control than any irons we have ever tested. The evolution of the proven Big Bertha design. None of the performance benefits in these irons would have been possible without the incorporation of the core design features common to the original Big Bertha Irons: 0 Our patented S21-12 (Short Straight Hollow Hosel) concept and TruBore technology, that allow us to take weight from where it is useless and put it where it is needed most. Our 360-clegree undercut channel and big, consistently thin face with its large, effective hitting area for greater forgiveness. Put it all together and you've got Callaway Golf's best irons to date -the best for amateurs of all skills and the best for pros with the greatest skills.
The ultimate titanium driver is now the ultimate success story. 1997 was a big year for the Biggest Big Bertha Titanium Driver. The popularity and acceptance of the Biggest Big Bertha Driver has surpassed even our expectations and then some. Golfers around the world have discovered the many benefits of using the Biggest Big Bertha Driver. But understanding why this driver has become so popular with players of every skill level requires a closer look at the design breakthroughs that went into it. The Biggest Big Bertha Driver is the latest improvement brought about by Callaway Golf-using innovations that began in 1991 with the original Big Bertha Drivers. The original driver featured the exclusive S2H2 (Short Straight Hollow Hose[) and Tru-Bore technology. With this revolutionary design we incorporated super-strong, super-light titanium to create this most satisfying driver. Next, we borrowed extensively from our development and testing of the Great Big Bertha Tungsten* Titanium Irons, the most extensive testing ever undertaken by Callaway Golf. From this we learned that just as there's an ideal size for an iron, there's an optimal size for a driver, too. Finally, to complement the greatly enlarged titanium clubhead, we developed shafts designed specifically for the Biggest Big Bertha Driver that allowed us to do the seemingly impossible- increase clubhead size (by 15% over the Great Big Bertha Driver) and shaft length (by onehalf inch compared with the Great Big Bertha Driver) while actually decreasing overall weight. Feel more confidence off the tee than with any other driver. The large, good-looking clubhead of the Biggest Big Bertha Driver gives many golfers a feeling of confidence they may have never before experienced with a driver. Because of the Biggest Big Bertha's enormous sweet spot and oversized hitting area, many players report feeling like they "just can't miss." Getting the ball airborne has never been easier.
For a lot of average golfers, simply getting the ball airborne off the tee can be an intimidating challenge. Not with the Biggest Big Bertha Driver. With its unique internal weighting system and optimal center of gravity, it makes getting proper ball-flight and trajectory easier than ever before. Achieve greater distance without swinging harder. The 451h" shaft length of the Biggest Big Bertha Driver helps generate increased clubhead speed, which in turn delivers increased distance, all without swinging any harder than usual. Eliminating the need to "over swing" results in fewer off-center hits, as well. Plus, the super ultralight shaft-our lightest ever-decreases overall weight and re-distributes it to the clubhead, where you need it most. Eliminate the fear of the driver. It's no secret that, for many golfers, their driver is the most difficult club to hit. That is, until they try a Biggest Big Bertha. This model is so easy to swing and so forgiving that many players never feel the urge to tee off with a 3-wood again. So, they choose the Biggest Big Bertha Driver.