Phil Mickelson raving about his new Callaway Big Bertha driver

Callaway Big Bertha Alpha driver
Courtesy of Callaway Golf
Phil Mickelson's Big Bertha Alpha driver from Callaway Golf has a ''gravity core'' that fits in a carbon tube in the head that connects the crown and sole and allows golfers to adjust the center of gravity location.
By John Holmes
PGA.com

Series: Golf Buzz

Published: Tuesday, January 14, 2014 | 6:09 p.m.
Phil Mickelson opens his 2014 campaign this week at the Abu Dhabi HSBC Golf Championship after a nice, long break. But instead of kicking back and putting his feet up, Mickelson spent a lot of time doing what he does better than perhaps anyone else on tour – tinkering with his clubs.
 
Mickelson, well known for his creative use of various drivers and fairway woods over the years, has a brand-new driver in his bag, and he was raving about it in Abu Dhabi on Tuesday.
 
"As I look back on 2013, I played some of my best golf and had some huge breakthroughs, but I did most of it without a driver," he said. "This year I have the best driver I've ever hit that lowers my spin rate just like my 3-wood. I drive it longer and straighter with my driver than I did with my 3-wood."
 
The object of Phil's affection is the brand-new Callaway Big Bertha Alpha, one of two Big Bertha versions that Callaway has recently introduced. The Alpha model that Mickelson is using contains a ''gravity core'' that fits in a carbon tube in the head that connects the crown and sole. It has a glass fiber-reinforced body that weighs in at 1.5 grams connected to a tungsten end weighing 10.5 grams. 
 
Either end of the core can be inserted into the clubhead, allowing golfers to raise or lower the center of gravity and thereby alter their spin rate. When the heavy tungsten end is closest to the sole, it lowers the center of gravity and reduces backspin; when the tungsten end is closest to the crown, it raises the center of gravity and increases spin.
 
 
Mickelson has positioned the gravity core in the low center of gravity position, according to Callaway.
 
Generally speaking, players with above-average head speeds or those trying to prevent excessive spin will benefit from that lower center of gravity, which a creates a flatter, more penetrating trajectory accompanied by more rollout, Callaway explains. Golfers looking for a more controlled and workable ball flight and less roll, they add, might be better served by using the higher center of gravity.
 
How much difference can the center of gravity placement make? Player testing has shown as much as a 600 rpm spin differential between the two settings without a change in loft, Callaway said.
 
The Big Bertha Alpha also enables golfers to adjust its center of gravity bias, which helps influence shot shape. The driver has screw ports in the heel and toe, and comes with four interchangeable weights of 1, 3, 5, and 7 grams that provide a lot of flexibility in controlling both shot shape and overall head weight. The 1g and 7g screws are installed as standard and deliver a D3 swingweight, but the swingweight can be adjusted from D0 to D5.
 
"It's a whole different weapon in my arsenal now," Mickelson said in Abu Dhabi. "And if I drive the ball well, like I have been in practice and in the off-season, heading into this 2014 season it could be the best year of my career for that simple reason."