What is Waggle Factor

By Frank ThomasFebruary 25, 2010, 7:10 pm

Hi Frank,

You recently talked about wearing a glove and how it can affect the swing weight of a club, and I imagine wearing a watch might do the same? But my real questions are: What is swing weight? How does it affect the quality of the swing or the results? And how do I know/figure out what is the proper swing weight for me?

Thank you very much

– Brian

Brian,

To your first question; What is swing weight?

A great amateur golfer, Francis Ouimet, won various events which included the U.S. Open in 1913. He selected his clubs based on feel – an undefined term but most of us seem to have a general idea what it means. If you waggle the clubs in your set, they should all feel the same, i.e. have the same waggle factor.

Because Francis Ouimet was such a good golfer, his clubs – matched by feel-- were used to develop a balance system. This was done by hanging a weight (approximately 16 ounces) on the grip end of each club and finding a common balance point (fulcrum) from the butt end for each club. This balance point was 14 inches from the butt. Thus, the swing weight system was born in about 1920 and still used today. The swing weight is not described as the amount of weight needed to balance a club but by an alpha-numeric table such as D2 or C9 etc.

Swing weight is a questionable system for several reasons. First, it implies a dynamic measurement which it is not. Second, it can be abused by back weighting or adding weight down the shaft purely to get the same or desired number. Third, it is not very well understood.

Having said this, it must be noted that pure swing weight – variations in shaft length and head weight only – is a good first step in matching clubs, as this is closely related to the waggle factor a term I coined because it is so descriptive.

This waggle factor should be called matching by moment of inertia (MOI). This is a much better method of matching clubs as it takes into account the weight, length and is a true dynamic measurement. If you hold a club at the grip end and waggle it, you will experience a specific resistance every time you change direction back and forth. This relates directly to the MOI of the club about the axis you are waggling it i.e. the grip.

Now turn the club around, holding its head and waggle it. You will find the resistance to changing direction is reduced significantly. The MOI has changed and it feels different. Francis Ouimet, unbeknownst to him, was matching his clubs by the MOI method –  the waggle factor.

Most of us know, having mentioned it several  times in Q&As over the last year, that wearing a glove will alter (decrease) the swing weight of the club by about five points, but will not noticeably affect the feel of the club.
The glove will not change the waggle factor (MOI) measurably.

Brian, now that we are over that explanation, let me say that in general terms the higher the swing weight (pure swing weight), the heavier the head and the more resistance you will feel to swinging the club to generating the same head speed.

After about 400 years of trial and error we have found that a swing weight in the range of about D0 to D3 is a good number for most male golfers. Females generally migrate to about C6 to C9. This, in most cases, is because the shaft length is about 1-inch shorter than men but the head weight is about the same.

So Brian a good starting point for you – as for most men -- is about a D0 or D2.

I am sure we will soon be matching clubs by MOI, which uses a relatively simple scale and takes into account all those variables used in swing weight, but is a dynamic measurement and more meaningful.

Waggle your way around this one, Brian.

– Frank

 

Frank Thomas, inventor of the graphite shaft, is founder of Frankly Golf. Thomas is chief technical advisor to GolfChannel.com. He served as technical director of the USGA for 26 years and directed the development of the GHIN system and introduced the Stimpmeter. To email a question for possible use in an upcoming Let's Be Frank column, please email letsbefrank@franklygolf.com

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Day WDs from Farmers pro-am because of sore back

By Golf Channel DigitalJanuary 24, 2018, 12:07 am

SAN DIEGO – Jason Day has withdrawn from the Wednesday pro-am at the Farmers Insurance Open, citing a sore back.

Day, the 2015 champion, played a practice round with Tiger Woods and Bryson DeChambeau on Tuesday at Torrey Pines, and he is still expected to play in the tournament.

Day was replaced in the pro-am by Whee Kim. 

Making his first start since the Australian Open in November, Day is scheduled to tee off at 1:30 p.m. ET Thursday alongside Jon Rahm and Brandt Snedeker.

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Farmers inks 7-year extension through 2026

By Golf Channel DigitalJanuary 24, 2018, 12:04 am

SAN DIEGO – Farmers Insurance has signed a seven-year extension to serve as the title sponsor for the PGA Tour event at Torrey Pines, it was announced Tuesday. The deal will run through 2026.

“Farmers Insurance has been incredibly supportive of the tournament and the Century Club’s charitable initiatives since first committing to become the title sponsor in 2010,” PGA Tour commissioner Jay Monahan said.


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“We are extremely grateful for the strong support of Farmers and its active role as title sponsor, and we are excited by the commitment Farmers has made to continue sponsorship of the Farmers Insurance Open for an additional seven years.

In partnership with Farmers, the Century Club – the tournament’s host organization – has contributed more than $20 million to deserving organizations benefiting at-risk youth since 2010. 

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Woods impresses DeChambeau, Day on Tuesday

By Ryan LavnerJanuary 23, 2018, 11:27 pm

SAN DIEGO – Bryson DeChambeau played with Tiger Woods for the first time Tuesday morning, and the biggest surprise was that he wasn’t overcome by nerves.

“That’s what I was concerned about,” DeChambeau said. “Am I just gonna be slapping it around off the tee? But I was able to play pretty well.”

So was Woods.

DeChambeau said that Woods looked “fantastic” as he prepares to make his first PGA Tour start in a year.

“His game looks solid. His body doesn’t hurt. He’s just like, yeah, I’m playing golf again,” DeChambeau said. “And he’s having fun, too, which is a good thing.”

Woods arrived at Torrey Pines before 7 a.m. local time Tuesday, when the temperature hadn’t yet crept above 50 degrees. He warmed up and played the back nine of Torrey Pines’ South Course with DeChambeau and Jason Day.

“He looks impressive; it was good to see,” Day told PGATour.com afterward. “You take (Farmers) last year and the Dubai tournament out, and he hasn’t really played in two years. I think the biggest thing is to not get too far ahead, or think he’s going to come back and win straight away.


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“The other time he came back, I don’t think he was ready and he probably came back too soon. This time he definitely looks ready. I think his swing is really nice, he’s hitting the driver a long way and he looks like he’s got some speed, which is great.”

Woods said that his caddie, Joe LaCava, spent four days with him in South Florida last week and that he’s ready to go.

“Before the Hero I was basically given the OK probably about three or four weeks prior to the tournament, and I thought I did pretty good in that prep time,” Woods told ESPN.com, referring to his tie for ninth in the 18-man event.

“Now I’ve had a little more time to get ready for this event. I’ve played a lot more golf, and overall I feel like I’ve made some nice changes. I feel good.”

Woods is first off Torrey Pines’ North Course in Wednesday’s pro-am, scheduled for 6:40 a.m. local time. 

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With blinders on, Rahm within reach of No. 1 at Torrey

By Rex HoggardJanuary 23, 2018, 10:10 pm

SAN DIEGO – The drive over to Torrey Pines from Palm Springs, Calif., takes about two and a half hours, which was plenty of time for Jon Rahm’s new and ever-evolving reality to sink in.

The Spaniard arrived in Southern California for a week full of firsts. The Farmers Insurance Open will mark the first time he’s defended a title on the PGA Tour following his dramatic breakthrough victory last year, and it will also be his first tournament as the game’s second-best player, at least according to the Official World Golf Ranking.

Rahm’s victory last week at the CareerBuilder Challenge, his second on Tour and fourth worldwide tilt over the last 12 months, propelled the 23-year-old to No. 2 in the world, just behind Dustin Johnson. His overtime triumph also moved him to within four rounds of unseating DJ atop the global pecking order.

It’s impressive for a player who at this point last year was embarking on his first full season as a professional, but then Rahm has a fool-proof plan to keep from getting mired in the accolades of his accomplishments.

“It's kind of hard to process it, to be honest, because I live my day-to-day life with my girlfriend and my team around me and they don't change their behavior based on what I do, right?” he said on Tuesday at Torrey Pines. “They'll never change what they think of me. So I really don't know the magnitude of what I do until I go outside of my comfort zone.”

Head down and happy has worked perfectly for Rahm, who has finished outside the top 10 in just three of his last 10 starts and began 2018 with a runner-up showing at the Sentry Tournament of Champions and last week’s victory.

According to the world ranking math, Rahm is 1.35 average ranking points behind Johnson and can overtake DJ atop the pack with a victory this week at the Farmers Insurance Open; but to hear his take on his ascension one would imagine a much wider margin.

“I've said many times, beating Dustin Johnson is a really, really hard task,” Rahm said. “We all know what happened last time he was close to a lead in a tournament on the PGA Tour.”


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Rahm certainly remembers. It was just three weeks ago in Maui when he birdied three of his first six holes, played the weekend at Kapalua in 11 under and still finished eight strokes behind Johnson.

And last year at the WGC-Mexico Championship when Rahm closed his week with rounds of 67-68 only to finish two strokes off Johnson’s winning pace, or a few weeks later at the WGC-Dell Technologies Match Play when he took Johnson the distance in the championship match only to drop a 1-up decision to the game’s undisputed heavyweight.

As far as Rahm has come in an incredibly short time - at this point last year he ranked 137th in the world - it is interesting that it’s been Johnson who has had an answer at every turn.

He knows there’s still so much room for improvement, both physically and mentally, and no one would ever say Rahm is wanting for confidence, but after so many high-profile run-ins with Johnson, his cautious optimism is perfectly understandable.

“I'll try to focus more on what's going on this week rather than what comes with it if I win,” he reasoned when asked about the prospect of unseating Johnson, who isn’t playing this week. “I'll try my best, that's for sure. Hopefully it happens, but we all know how hard it is to win on Tour.”

If Rahm’s take seems a tad cliché given the circumstances, consider that his aversion to looking beyond the blinders is baked into the competitive cake. For all of his physical advantages, of which there are many, it’s his keen ability to produce something special on command that may be even more impressive.

Last year at Torrey Pines was a quintessential example of this, when he began the final round three strokes off the lead only to close his day with a back-nine 30 that included a pair of eagles.

“I have the confidence that I can win here, whereas last year I knew I could but I still had to do it,” he said. “I hope I don't have to shoot 30 on the back nine to win again.”

Some will point to Rahm’s 60-footer for eagle at the 72nd hole last year as a turning point in his young career, it was even named the best putt on Tour by one publication despite the fact he won by three strokes. But Rahm will tell you that walk-off wasn’t even the best shot he hit during the final round.

Instead, he explained that the best shot of the week, the best shot of the year, came on the 13th hole when he launched a 4-iron from a bunker to 18 feet for eagle, a putt that he also made.

“If I don't put that ball on the green, which is actually a lot harder than making that putt, the back nine charge would have never happened and this year might have never happened, so that shot is the one that made everything possible,” he explained.

Rahm’s ability to embrace and execute during those moments is what makes him special and why he’s suddenly found himself as the most likely contender to Johnson’s throne even if he chooses not to spend much time thinking about it.