Hot Drivers and COR

By Frank ThomasJanuary 31, 2006, 5:00 pm
Frankly GolfEditor's Note: This is the latest in a new weekly feature from Golf Channel Chief Technical Advisor Frank Thomas. To submit a question for possible use in this column, email
Mr. Thomas,
I have two questions related to COR (Coefficient of Restitution). The USGA ruled that a .83 COR was the maximum they would allow in a driver face for legal tournament play. However, until 2008, the R & A (Royal and Ancient) governing board still allows a driver up to a .86 COR.

1) When a USGA pro plays at St. Andrews, or some other course that is governed by R & A rules, are they allowed to use a driver with a higher COR?

2) Can the COR of a driver vary based on the temperature of the club face? If so, by how much?

Best regards, Chris, IL

There is no limit on the COR for drivers, other than in championship play, in countries under the jurisdiction of the R&A. The R&A does enforce the .830 limit for championship play and recommends that all PGA events adopt the same limit. The maximum COR is governed by the Laws of Physics and the (unachievable) limit is 1.00.
Almost every manufacturer is making drivers for the market outside the USA and these vary between .830 and up to .900 I am told. It is going to be interesting to see what happens on January 1st 2008 when the rules will change for the R&A (Royal and Ancient Golf Club of St. Andrews) to mimic those of the USGA and all drivers must conform to the .830 limit. If the masses of golfers dont give up the clubs they purchased (maybe only six months earlier) then we have open defiance of the rules, which dilutes the authority of the governing body and also makes it so much easier to violate another rule. The problem, as I see it, is that once the club has been in use, without being a violation of the rules, one is inclined to believe that it will be OK forever, especially if it has a benefit perceived or otherwise.
By the way, the perceived increase in distance that .860 will give the golfer over .830 is probably eight to ten times the real achievable increase. Temperature does not have a measurable effect on the COR in the range of normal golf weather. To learn more about COR visit
Why do most pro golfers and others, cover their driver, fairway woods and putter, but not their irons? Is it necessary to cover the golf clubs? What are the advantages or disadvantages?
Thank you, Carlito, California

The only reason why anybody covers (head covers) their clubs is to protect them. Generally the putter and the woods are more likely to get dinged than the irons and this is the only reason for covering (protecting) them, not to keep a hot driver hot. Wood head covers were originally designed for wooden clubs for the same reason i.e. to protect the fine finish and thus prevent them from absorbing moisture. With todays oversize metal heads it is becoming more difficult to find a big enough head cover that is easy to put on and take off. Manufacturers seem to be doing a better job, however, in some cases it looks like the head cover costs almost as much as the club it is covering. You may find some golfers who are very particular about their irons and they have rubberized head covers but this is the exception.
What is the origin of the rule on damaged clubs and how can it possibly benefit a player, such as Kevin Stadler, to have a damaged club in his bag? -- Juliet, CO
The rule requires that a shaft must be straight. If it is accidentally bent in the normal course of play (not in anger) the player may continue to use it for the remainder of the round even though it does not conform, or the club may be repaired without delaying play. However, a club which was damaged during a round and is non conforming due to the damage must be repaired to the point where it conforms before using it in a subsequent round.
In most cases a damaged club is not going to help any way so get it fixed as soon as possible to help your game and stay on the right side of the rules.
My swing speed is right around 90 mph, my back swing is slow and deliberate, but on my downswing I try to rip the balls head off. My drives seem to go rather short and definitely fade; my average drive is around 200 yards with carry and roll. Should I be hitting it around 220 carry and around 230 with any kind of roll? So my question is would I be better off with a senior flex shaft? -- Rick, Kentucky

I think a regular shaft flex is fine and you should be driving the ball farther than 200 yards with a head speed of 90 mph. To correct the fade you may need a slight swing correction. But the distance problem is probably the incorrect launch conditions. You ball speed should be close to 130 mph and a launch angle of about 13 to 14 degrees and the spin rate of about 3,000 rpm.
If you dont have these conditions then see what a different head design would do. Eleven or 12 degree loft would be a good start.
Frank Thomas, inventor of the graphite shaft, is founder of Frankly Golf, a company dedicated to Helping Golfers. Frank is Chief Technical Advisor to The Golf Channel and Golf Digest. He served as Technical Director of the USGA for 26 years and directed the development of the GHIN System and introduced the Stimpmeter to the world of golf. To email a question for possible use in an upcoming Let's Be Frank column, please email
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What's in the bag: CareerBuilder winner Rahm

By Golf Channel DigitalJanuary 22, 2018, 10:37 pm

Jon Rahm defeated Andrew Landry in a playoff to earn his second PGA Tour title at the CareerBuilder Challenge. Here's what's in his bag:

Driver: TaylorMade M4 (9.5 degrees), with Aldila Tour Green 75 TX shaft

Fairway wood: TaylorMade M3 (19 degrees), with Aldila Tour Green 75 TX shaft

Irons: TaylorMade P790 (3), P750 (4-PW), with Project X 6.5 shafts

Wedges: TaylorMade Milled Grind (52, 56 degrees), Milled Grind Hi-Toe (60 degrees), with Project X 6.5 shafts

Putter: TaylorMade Spider Tour Red

Ball: TaylorMade TP5x

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Strange irked by Rahm-Landry friendly playoff

By Jason CrookJanuary 22, 2018, 9:45 pm

Curtis Strange knows a thing or two about winning golf tournaments, and based on his reaction to the CareerBuilder Challenge playoff on Sunday, it’s safe to say he did things a little differently while picking up 17 PGA Tour victories in his Hall-of-Fame career.

While Jon Rahm and Andrew Landry were “battling” through four extra holes, Strange, 62, tweeted his issues with the duo’s constant chit-chat and friendly banter down the stretch at La Quinta Country Club, where Rahm eventually came out on top.

The two-time U.S. Open champ then engaged with some followers to explain his point a little more in depth.

So, yeah ... don't think he's changing his perspective on this topic anytime soon ever.

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Randall's Rant: The Euros won't just roll over

By Randall MellJanuary 22, 2018, 9:36 pm

The Ryder Cup may not be the King Kong of golf events yet, but you can hear the biennial international team event thumping its chest a full eight months out.

As anticipation for this year’s big events goes, there is more buzz about Europe’s bid to hold off a rejuvenated American effort in Paris in September than there is about the Masters coming up in April.

Thank Europe’s phenomenal success last weekend for that.

And Rory McIlroy’s impassioned remarks in Abu Dhabi.

And the provocative bulletin board material a certain Sports Illustrated writer provided the Europeans a couple months ago, with a stinging assault on the Euro chances that read like an obituary.

McIlroy was asked in a news conference before his 2018 debut last week what he was most excited about this year.

The Ryder Cup topped his list.

Though McIlroy will be trying to complete the career Grand Slam at Augusta National come April, he talked more about the Ryder Cup than he did any of the game’s major championships.

When asked a follow-up about the American team’s resurgence after a task-force overhaul and the injection of young, new star power, McIlroy nearly started breaking down the matchup. He talked about the young Americans and how good they are.

“Yeah, the Americans have been, obviously, very buoyant about their chances and whatever, but it’s never as easy as that. ... The Ryder Cup’s always close,” McIlroy said. “I think we’ll have a great team, and it definitely won’t be as easy as they think it’s going to be.”

McIlroy may have been talking about Alan Shipnuck’s bold prediction after the American Presidents Cup rout last fall.

Or similar assertions from TV analysts.

“The Ryder Cup is dead – you just don’t know it yet,” Shipnuck wrote. “One of the greatest events in sport is on the verge of irrelevancy. The young, talented, hungry golfers from the United States, benefitting from the cohesive leadership of the Task Force era, are going to roll to victory in 2018 in Paris.”

European Ryder Cup captain Thomas Bjorn won’t find words that will motivate the Euros more than that as he watches his prospective players jockey to make the team.

And, boy, did they jockey last weekend.

The Euros dominated across the planet, not that they did it with the Ryder Cup as some rallying cry, because they didn’t. But it was a heck of an encouraging start to the year for Bjorn to witness.

Spain’s Jon Rahm won the CareerBuilder Challenge on the PGA Tour, England’s Tommy Fleetwood started the week at Abu Dhabi paired with American and world No. 1 Dustin Johnson and won the European Tour event, and Spain’s Sergio Garcia won the Singapore Open in a rout on the Asian Tour.

And McIlroy looked close to being in midseason form, tying for third in his first start in three months.

Yes, it’s only January, and the Ryder Cup is still a long way off, with so much still to unfold, but you got an early sense from McIlroy how much defending European turf will mean to him and the Euros in Paris in September.

The Masters is great theater, the U.S. Open a rigorous test, The Open and the PGA Championship historically important, too, but the Ryder Cup touches a nerve none of those do.

The Ryder Cup stokes more fervor, provokes more passion and incites more vitriol than any other event in golf.

More bulletin board material, too.

Yeah, it’s a long way off, but you can already hear the Ryder Cup’s King Kong like footsteps in its distant approach. Watching how the American and European teams come together will be an ongoing drama through spring and summer.

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Quail Hollow officials promise players easier conditions

By Rex HoggardJanuary 22, 2018, 9:14 pm

Quail Hollow Club - a staple on the PGA Tour since 2003 - debuted as a longer, tougher version of itself at last year’s PGA Championship, receiving mixed reviews from players.

The course played to a lengthened 7,600 yards at last year’s PGA and a 73.46 stroke average, the toughest course in relation to par on Tour in 2017. As a result, it left some players less than excited to return to the Charlotte, N.C.-area layout later this spring for the Wells Fargo Championship.

It’s that lack of enthusiasm that led officials at Quail Hollow to send a video to players saying, essentially, that the course players have lauded for years will be back in May.

The video, which includes Quail Hollow president Johnny Harris and runs nearly five minutes, begins with an explanation of how the first hole, which played as a 524-yard par 4 at the PGA, will play much shorter at the Wells Fargo Championship.

“I had a number of my friends who were playing in the tournament tell me that tee was better suited as a lemonade stand,” Harris joked of the new tee box on the fourth hole. “I doubt we’ll ever see that tee used again in competition.”

Harris also explained that the greens, which became too fast for some, will be “softer” for this year’s Wells Fargo Championship.