Rational Blog: Thoughts on Golf and the World

Bryson DeChambeau's single length irons

By Gisle Solhaug |

Bryson DeChambeau's single length irons are all matched. The BioMatch method of matching golf clubs determines the optimum mass of each club in the set. The optimum mass is a function of club length, club moment of inertia, and lie angle as well as the properties of the golfer. As all these variables are identical for all of Bryson DeChambeau's irons, the BioMatch method will yield the same optimum weight for all his irons. As all his irons do have the same weight, they are matched according to the BioMatch method.

Unfortunately only his irons are matched. The rest of his clubs can easily be matched by the BioMatch method so that he can use the same swing for all his clubs, without altering the length of the clubs or the weight of the club heads.  The optimum weight of each club is obtained by inserting the appropriate size of weight into the grip end of the club.

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Tiger Woods Withdraws

By Gisle Solhaug |

Tiger Withdraws

On Friday, I posted an article to my blog in excitement of the return of Tiger Woods to golf. Unfortunately, Tiger has withdrawn from the Safeway Open. On Monday, Woods stated that “his game was vulnerable”. “After a lot of soul searching and honest reflection, I know that I am not yet ready to play on the PGA Tour or compete in Turkey,” Woods said in a statement. “My health is good, and I feel strong, but my game is vulnerable and not where it needs to be. It’s not up to my standards, and I don’t think it would be up to yours.”

This saddening news for many came just three days after he committed to playing in the Safeway Open and three days before the open is setting to take place. Speaking earlier Monday on Golf Channel, Notah Begay III said that Woods had "some concerns about the sharpness of his game" after sitting out the past 14 months. “He just didn’t feel like his game is where he wanted it to be to be competitive," Begay said.

“This isn’t what I wanted to happen,” he said, “but I will continue to strive to be able to play tournament golf. I’m close, and I won’t stop until I get there.”

It looks like the wait for Tiger to return to golf will continue to be highly anticipated.

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Tiger Woods Returns to Golf

By Gisle Solhaug |

Tiger Woods announced on Friday, October 7, 2016 that he will be returning to the PGA Tour. Woods will participate in the Safeway Open, which begins October 13th. In a website update, he states that he hopes to play in the European Tour’s Turkish Airlines Open, held November 3-6. As well as the Hero World Challenge held December 1-4. This is all dependent on his physical recovery.

After his las competitive play at the Wyndham Championship, in 2015, Woods underwent two back surgeries. At his appearance at the Ryder Cup last week, Woods gave no indication of his intentions to play, nor the condition of his health. However, his play of the course showed him to be ready for a return. Before teeing up at the Safeway Open, Woods will participate in the Tiger Woods Invitational, held October 10-11 on the Monterey Peninsula. From there he will kick-start a return to golf that everyone has anxiously been waiting for since over a year ago!

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Ryder Cup 2016 Final Results

By Gisle Solhaug |

The 41st Ryder Cup more than lived up to expectations as the United States on Sunday clinched its first crown since 2008, winning Sunday singles 7.5-4.5 to capture the cup by a 17-11 margin. The United States is now home to the Ryder Cup for the first time since 2008, and Davis Love III improves to 1-1 as the American captain, getting revenge for the 2012 collapse at Medinah.

Reed wins 1 Up vs. McIlroy

Stenson wins 3&2 vs. Spieth

Pieters wins 3&2 vs. Holmes

Cabrera Bello wins 3&2 vs. Walker

Fowler wins 1 Up vs. Rose

Koepka wins 5&4 vs. Willett

Mickelson ties Garcia

Snedeker wins 3&1 vs. Sullivan

Moore wins 1 Up vs. Westwood

Z Johnson wins 4&3 vs. Fitzpatrick

DJohnsons wins 1 Up vs. Wood

Kaymer wins 1 Up Kuchar

Here are the individual records for each player on both teams.

United States               Record (points)                Europe               Record (points)

Patrick Reed                  3-1-1 (3.5)                 Thomas Pieters         4-1-0 (4)  Brandt Snedeker            3-0-0 (3)                    Rory McIlroy              3-2-0 (3) Brooks Koepka               3-1-0 (3)                    Rafa Cabrera Bello   2-0-1 (2.5)    Phil Mickelson                2-1-1 (2.5)                 Henrik Stenson          2-3-0 (2)       Jordan Spieth                 2-2-1 (2.5)                 Justin Rose               2-3-0 (2) Ryan Moore                   2-1-0 (2)                    Sergio Garcia            1-2-2 (2) Rickie Fowler                 2-1-0 (2)                    Chris Wood                1-1-0 (1) Zach Johnson                2-1-0 (2)                    Martin Kaymer            1-3-0 (1) Dustin Johnson             2-2-0 (2)                    Andy Sullivan              0-2-0 (0) Matt Kuchar                  2-2-0 (2)                    Matthew Fitzpatrick     0-2-0 (0) J.B. Holmes                  1-2-0 (1)                    Danny Willett               0-3-0 (0) Jimmy Walker               1-2-0 (1)                    Lee Westwood            0-3-0 (0)


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Ryder Cup 2016 Friday's Results

By Gisle Solhaug |

After a dominant performance in morning session foursomes in which the United States swept Europe 4-0, the Americans saw their lead cut to 5-3 following a tremendous showing from the Europeans in the afternoon four-ball matches.

Friday's Scores Foursomes Results (United States 4-0):

Patrick Reed/Jordan Spieth (USA) win 3&2 over Justin Rose/Henrik Stenson

Dustin Johnson/Matt Kuchar (USA) win 5&4 over Thomas Pieters/Lee Westwood

Zach Johnson/Jimmy Walker (USA) win 4&2 over Segio Garcia/Martin Kaymer

Rickie Fowler/Phil Mickelson (USA) win 1 Up over Rory McIlroy/Andy Sullivan

Four-ball Results (Europe 3-1)

Justin Rose/Henrik Stenson (Europe) win 5&4 over Patrick Reed/Jordan Spieth

Sergio Garcia/rafa Cabrera Bello (Europe) win 3&2 over J.B. Holmes/Ryan Morre

Brandt Snedeker/Brooks Koepka (USA) win 5&4 over Martin Kaymer/Danny Willett

Rory McIlroy/Thomas Pieters (Europe) win 3&2 over Dustin Johnson/Matt Kuchar


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Driving Range Etiquette

By Gisle Solhaug |

To be successful in a game as difficult as golf, you need to practice. Very few people can head out for a round and post a good score without working on their game beforehand. Practicing at a driving range is a perfect way to get better, but there are some things to remember. You need to follow the rules and be courteous of the facility and others joining you on the range.

Respect the Facility

Some driving ranges require that you hit from a mat, while others allow you to hit off the grass. It is very important to follow the rules. Stay within the boundaries. Hit each ball close to where you hit the last one to minimize damage.  


Be aware of your surroundings. Stay far away from others to minimize the risk of hitting anyone. Before you swing, look around to make sure that nobody is behind you or walking by. Never walk out on the range to retrieve balls.

Be Courteous

Remember that you are sharing the range with others. Keep the noise level down and remember to keep your cell phone set to vibrate. Avoid sudden movements around a player who is about to swing.

Care for the Greens

Most driving range facilities also offer putting greens and short-game areas for people wanting to work on chipping and putting. Treat these areas as you would a green on the golf course. Do not chip on to the greens from the driving range.

By keeping these tips in mind regarding etiquette at the driving range, you will ensure that you and all other golfers will have a pleasant experience.





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Ryder Cup 2016

By Gisle Solhaug |

Ryder Cup (Named after the English businessman Samuel Ryder who donated the trophy.)

The Ryder Cup has become one of the world’s greatest sporting events. It’s Team USA vs. Team Europe, as 24 of the world’s best golfers play for pride, patriotism, and the most coveted cup in golf. The competition is every two years with the venue alternating between courses in the US and Europe. A three-day competition that includes head to head match play, the team that gets to 14 out of 28 available points will take home the Ryder Cup. Don’t miss a moment, September 30 to October 2, only on Golf Channel and NBC, as Team USA fights to reclaim the cup at home. Golf Channel will be there from the beginning, live from Hazeltine National Golf Club, in Chaska, Minnesota.

Schedule (All times Eastern and airing on Golf Channel and NBC)

Friday 10:30AM-1PM: Day 1, morning session 3-6PM:  Day 1, afternoon session

Saturday, October 1 10:30AM-1PM: Day 2, morning session 3-6PM: Day 2, afternoon session

Sunday, October 2 2-5:30PM: Day 3 singles

USA Players Captain • Davis Love III Vice-Captains • Jim Furyk • Tom Lehman • Steve Stricker • Bubba Watson • Tiger Woods Players • Ricki Fowler (Captain’s Pick) • J.B. Holmes (Captain’s Pick) • Dustin Johnson • Zach Johnson • Brooks Koepka • Matt Kuchar (Captain’s Pick) • Phil Mickelson • Ryan Moore (Captain’s Pick) • Patrick Reed • Brandt Snedeker • Jordan Spieth • Jimmy Walker

Europe Team Captain • Darren Clarke Vice-Captains • Thomas Bjorn • Padraig Harrington • Paul Lawrie • Ian Poulter • Sam Torrance Players • Rafa Cabrera Bello • Matthew Fitzpatrick • Sergio Garcia • Marin Kaymer (Captain’s Pick) • Rory McIlroy • Thomas Pieters (Captain’s Pick) • Justin Rose • Henrik Stenson • Andy Sullivan • Lee Westwood (Captain’s Pick) • Danny Willett • Chris Wood

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Do you Slice your Driver?

By Gisle Solhaug |

Most golfers have a problem slicing their Driver, but not the other clubs. This would, of course, not happen if all the clubs were matched. In a matched set of clubs, all the clubs will go straight, as long as you can hit any one club straight.  So why does the Driver slice? Because the moment of inertia of the Driver is too large compared to its overall weight.  This causes the hands to be too far forward at impact. In other words, you are hitting the ball with an open face.  As your hands are too far forward at impact position they are now on a path towards the left, away from the ball, causing a slice spin.

The large moment of inertia of the modern Driver is mainly caused by the increased length of the Driver.  In an attempt by golf club manufacturers to produce more distance, they have increased the length of the Driver.  This may work for you if you are able to steer the club with your wrists into a position where you can control the ball flight.  Steering should not be necessary.  It complicates the game as you have to steer each club differently, as they are not matched.  If your clubs are properly matched they should all behave as intended with relaxed wrists.  Relaxed wrists will also provide more distance.

Golf club manufacturers are fighting the open face by manufacturing Drivers with a closed face.  However, the slice spin remains as your hands are moving right to left at impact.  Some club manufacturers try to further reduce the slice by adding movable dead weight to the club heads.  The dead weight further increases the moment of inertia of the club which again will add to the problem.  When moving the weights around on the clubhead the center of gravity of the clubhead is no longer aligned with the geometric sweet spot, causing further problems.  This all adds up to a very unstable condition.  It is like trying to balance a ball on top of another ball.

When adding weight to the grip end of the club, your hands will slow down slightly.  And due to the added weight, you body will create more kinetic energy.  This added kinetic energy translates to added club head speed.  Meaning that your club will release faster making your club head catch up with your hands.  The BioMatch method of matching golf clubs calculates the exact weight to be added to each of your clubs for the club head to catch up with your hands exactly at the point of impact. 

The BioMatch method calculates the specific weight to be added to the grip end of all your clubs.  The BioMatch system is available online at www.rational-golf.com.  The weights that are specified in the BioMatch Report can be ordered by a click of a button.  The weights are easily installed with the accompanying tool.

It is a lot easier to learn and maintain one swing rather than 13.  BioMatch does magic to any golfer´s game.

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How to Calculate Swingweight with a Measuring Tape

How to Calculate Swingweight with a Measuring Tape

A drawing showing the forces acting on a golf club positioned in a Swingweight Scale is provided bellow. The three forces acting on the golf club are as follows:
The force F, acting downwards at the grip end of the club. This is the force measured by the Swingweight instrument.
The force G is the gravitational force acting on the golf club. It is simply the weight of the golf club acting at its center of gravity. The location of the center of gravity can be determined by balancing the club on a knife-edge. The center of gravity is located at distance BC from the fulcrum.
The third force is acting upward at the fulcrum. The fulcrum is located 356 mm (14 inches) from the grip end of the club. This force equals the sum of force G and force F, acting in the opposite direction.
From Newton´s Laws of Motion, it is established that the sum of all moments acting upon a body at rest is zero. By adding the moments acting on the golf club about the fulcrum in the Swingweight instrument, denoting clockwise as the positive direction: 
Sum of all moments = ∑M = (G x AB) - (F x 356 mm) = 0

F = G x AB / 356 mm 

The Swingweight of any golf club can thereby be calculated when the mass and center of gravity is known. Swingweight is purely a function of mass and center of gravity of the golf club. For example, a golf club is found to have a mass of 349.8 grams and a center of gravity located 824 mm from the grip end of the club. These measurements were carried out on an actual golf club using a scale, a knife-edge, and a measuring tape. From Newton´s second law of motion, the vector force G = 0.3498 Kg x 9.81 m/s^2 = 3.431 N. The distance AB = 824 mm – 356 mm = 468 mm = 0.468 m. Hence;
F = 3.431 N x 0.468 m / 0.356 m = 4.510 N
From a table that I will forward next, you can look up this number and see the Swingweight.


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Swingweight Table

Swingweight Table From the table, the calculated force corresponds to a Swingweight of D7.8. Measuring the club in a Digital Swingweight Scale gives the same Swingweight of D7.8. The club used for this example is a TaylorMade 5 hybrid. The fact that a letter scale and a measuring tape can replace the Swingweight Scale, which has been utilized for almost a century, will come as a big surprise to the majority of golf club fitters. This ought to raise some concerns even for the die-hard Swingweight supporters. As the center of gravity does not enter any equations describing circular motion, the Swingweight of a body cannot be related to how a body acts under circular motion. Newton’s second law of circular motion states: Torque = Moment of Inertia x Angular Acceleration. There is, therefore, no relationship between Swingweight and how a golf club behaves when acted upon by a golfer. Ever since the Swingweight principle was developed in the 1920s, it has been the accepted method for matching clubs within a set, so they all feel alike when swung. In short, it is a measurement of the weight distribution of the club. And with the introduction of lighter shafts, grips, and club heads, the possibility of a wider range of Swingweights, and thus more inconsistency from club to club is greater. When Robert Adams was matching his set of golf clubs by waggling the golf clubs in a horizontal plane, he was in fact attempting to measure the moment of inertia of the club around the center of the grip. The moment of inertia around the center of the grip is henceforth referred to as MOIG. One can imagine how difficult it would be to adjust all 13 clubs until they all felt like having the same MOIG. There were no instruments available for measuring the moment of inertia at the time. Robert Adams made an instrument that would provide an indication of whether all the clubs in a set of golf clubs would have similar MOIG. The clubs used to develop the swingweight method all had similar wooden shafts. That is no longer the case. The Swingweight system is therefore even less useful today than it was 90 years ago.

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