Collision!

Few golfers are aware of what really happens when a clubhead collides with a golf ball at high speed, not to mention how much an off-center collision can effect the flight of the ball. My hope is that this article and the accompanying video footage will give each of you a much better understanding of the importance of solid contact. I would encourage you to watch the following PGATour.com video a few times...

As you can see a strike away from the center of gravity of the clubhead will lead to twisting of the clubhead. While most of the twisting occurs after impact, a portion of it does occur during the impact interval. It is this twisting during impact that leads to gear effect which can greatly alter the flight of a shot.

An off-center collision will twist the clubface in any direction.

A hit high on the face will tilt the face upward and reduce the amount of spin on the ball, while a low strike point will deloft the face and increase spin rate. A strike towards the toe will open the clubface and increase draw or reduce fade and a strike towards the heel will close the face and increase fade or reduce draw. Interestingly, the clubface will tilt vertically (top/bottom) almost as much as it will horizontally (toe/heel).

There are seven shots in the video and if each of them had a neutral club face and club path during impact, the results of each shot due to gear effect would have been as follows:

Shot 1 - A strike above the "equator" of the clubface and slightly towards the toe. Ideal if you would like to hit high launching, low spinning, draws that go a long way.

A High Toe Strike

Shot 2 - A more pronounced high, toe side strike. This strike point is too far from aligning with the center of gravity of the clubhead to be beneficial. This flight due to gear effect would have been fairly high launching, low spinning and would not have faded as much as it might have appeared.

Shot 3 - Another extreme high, toe side strike along with a heavy descending blow - not good. High and right, but a fairly straight flight.

A Low Heel Side Strike

Shot 4 - A severely off-center hit where the collision is with a very low portion of the face and in the heel. Believe it or not this ball gets airborne and will almost always be an unimpressive high spinning,  low fade with very little distance.

Shot 5 - Charley Hoffman: I have seen numerous clips of high speed driver footage like this and I don't think I have ever seen one where I cannot detect any twisting at all. A slight downward attack angle. Appears to be very close to a perfect center of gravity strike - a truly rare event! Very straight.

Shot 6 - Matt Kuchar: A neutral attack angle along with a high, toe side strike. High launch, lower spin and a slight draw - boom!

Shot 7 - Luke Donald: About as solid as Charley Hoffman's shot, but the interesting thing about this clip is the attack angle - quite severely down. Solid and straight, but not optimal for maximum distance.

It is interesting to note that today's larger clubheads will resist twisting due to having a higher moment of inertia. MOI is a measure of a body’s resistance to angular acceleration or twisting. MOI really comes into play when the ball and the clubface meet someplace other than the sweet spot. The MOI of a club is higher for heel/toe mishits than it is for high/low mishits and therefore tends to be more forgiving on heel/toe mishits. However, golfers tend to mishit a shot further towards the heel/toe than they do high/low so the clubheads' resistance to twisting tends to even out.

Please know that physics is not selective and any golfer, pro or amateur, can hit any shot solidly or severely off-center. Also - no golfer can "stabilize" the clubface during or after impact due to an off-center strike.

This article shows you which part of the clubface is best.

I love this video footage and from here on out it will be required viewing for all my long term and golf school students. Would love to hear your thoughts....

The Hot Drivers and Shafts for 2013

It's always nice to get an unbiased opinion from an expert. As a result I recently spent some time with friend and clubfitting guru Ian Fraser from Modern Golf in Toronto Canada, discussing what he deemed to be the top driver and shaft options available for 2013. Ian has no affiliation with any one club or shaft manufacturer so I really value his opinions. Here are his selections for the top shafts available this year:

UST Mamiya Attas 4U

• higher launch and low spin
• stronger mid-section helps to increase ball speed

Graphite Design Tour AD BB

• BB - blue bullet
• designed to produce less spin with a lower launch

Fujikura Fuel

• designed with feedback from ENSO technology
• lower launching and lower spinning shaft
• excellent price point

I also wanted to hear Ian's take on the new crop of drivers that have been on the market for a few months now and he had some interesting things to say. Here are his choices:

Titleist 913 D2/D3

• improved design and ball speed over the 910 series
• D2 and D3 different in size, yet similar in spin rates

TaylorMade R1

• massive adjustability with very high ball speed
• slightly heavier than the R11S

Ping G25

• highest MOI of any driver available and best paint job!
• slightly less spin and higher ball speed than the G20

I suppose my optimal driver would one that had the looks of the Titleist 913 D3, the stability and matte black finish of the Ping G25 along with the adjustability and ball speed of the TaylorMade R1....one can dream!

Please be aware that going out and simply purchasing and combining one of the above options might not be the best thing for you. I would recommend getting with a professional clubfitter who uses TrackMan technology to find the appropriate head and shaft match for your particular swing. You should be looking for the optimal launch and spin characteristics that match your swing speed.

Read THIS to know where you should be launching and spinning the ball based on your current club speed.

Driver Test: Old vs. New

My wife encouraged me to clean out the garage the other day and I happened upon an old driver I used in college. I still remember how cool this driver was - it was the latest and greatest and even had a titanium shaft! When was the last time you saw one of those? Just for kicks I placed it up alongside my current Titleist driver and was shocked at the massive difference between the two - the older club looked smaller than my current three wood! How could I have possibly played well with this mini club? This got me thinking about a TrackMan test.

For the record the smaller club was a TaylorMade Burner Plus 9.5 degree with a titanium X flex shaft and my current club is a Titleist D3 8.5 with a Motore F3 70 gram graphite S flex shaft. There is a fairly substantial 1.5 inch difference even though both clubs were standard length in their day. I am not sure about the weight or the true frequency/flex of each club as I did not have the appropriate equipment to check those measurements.

For the TrackMan test I hit 12 shots with each club and deleted the data for the two worst shots. I noted that the attack angle, club path, swing direction and plane were very similar from club to club.

The primary differences seemed to be:

• Club speed 99.7mph vs 101.8mph - I believed that this difference would be greater due to the large difference in length of shafts.
• Ball Speed 145.7mph vs 152.4mph - I put this down to the fact that the smaller head led to more off-center hits and thus a decreased average ball speed and smash factor.
• Point of contact - there was a noticeable tendency for me to strike the bigger club in the heel. This led to more shots missed to the right due to gear effect and an increase in the spin rate 2455rpm vs 2895rpm.
• Height - even though the smaller club launched the ball slightly higher the apex height was lower due to less spin and ball speed.
• Carry and total distance - the smaller club carried the ball almost 17yards shorter, but with less spin and a flatter land angle rolled further to only finish just over 10 yards short of the bigger club.
• Dispersion - the smaller club had more shots finish further from the center line due to a much smaller clubface and substantially lower MOI.

Here are the TrackMan generated dispersion charts (yellow is the smaller club) and averages:

(click to enlarge)

I was amazed at how small the difference between the two drivers, total distance wise, there was. Going in to the test I would have thought that there would be a 15 yard difference at least. I expected the smaller club to spin the ball less and lower the apex which it did, but I was truly amazed at how little distance I lost with it. I did notice a much greater tendency to hit the ball outside the sweet spot with the smaller club and that led to some fairly aggressive gear effect draws and fades.

Driving is not my strong suit and I am always looking to keep the ball in play off the tee. Armed with this new knowledge I am going to try a shorter shaft in my current driver head and see what that does for my fairways hit statistic. I also plan on practicing with the older club - I think it is vital in improving ball striking to practice with smaller headed clubs.

I also think this test might also illustrate that the majority of the distance gains we see on the PGATour today are not equipment based, but primarily due to the ball.....your thoughts?

The Driver and Distance (Part 1)

We all want to hit the ball straight and far of the tee don't we?  In more technical terms our goals with the driver are to achieve the highest ball speed possible (distance), along with the desired flight pattern (accuracy).  We want cake and we want to eat it too!  There are numerous elements built into most drivers that often assist us in achieving these goals, yet so many of these small factors almost go unnoticed.  Almost...

Factors in driver technology that influence distance are: length of club; shaft weight; head weight; loft; face material and thickness (CoR) and roll (vertical gear effect).  Distance comes from our ability to convert clubhead speed into ball speed - often referred to as smash factor.  Smash factor is an indicator of our efficiency at impact - are we getting out what we (our driver included!) are putting in?

• It seems to be fashionable these days for club companies to stretch the length of their drivers to 46 inches and claim that they are "superfast".  The laws of physics indicate they are faster, but in my hands any speed gains are sacrificed with a loss of control.  Ben Hogan used a driver that was 42.5 inches long and nowhere have I ever read that he was a short hitter.  Personally I am not a fan of anything over 45 inches as this seems to be my threshold where distance decreases and control and centerdness of hit diminishes. I believe beginning golfers could use a 43 inch driver with far better results.
• Over the last decade shaft technology has come a long way and the most notable upgrade has been shaft weight.  Miyazaki makes an incredible 39 Series driver shaft that can be as light as 44 grams - if you you cannot swing that faster then we have a problem.  Barring feel and control issues I am a big fan of lightweight shaft technology and know it is something we should all take advantage of - even Keegan Bradley did.
• In pursuit of the "lighter is faster" formula a few companies have sought to reduce the weight of the clubhead.  Cleveland Golf has their Ultralight line of drivers that are the lightest on the market today.  A little known fact is that we could actually hit the ball further with a heavier clubhead (with speed being equal).  By increasing the mass ratio of clubhead to ball you can increase ball speed, however the problem here is that as you increase weight you decrease speed, so once again there is a threshold to consider.  The good news is the club companies have done all the research for us and most driver heads fall somewhere between 197 and 212 grams - something we can all manage.
• The loft of your driver is something that should be determined by an expert (someone who does this for a living!) fitter.  A nice option with the new adjustable heads is that you can now alter the loft of your club without buying a whole new club. The more loft you introduce to the ball at impact the more spin and less ball speed you will create.  The lower the loft, the more ball speed. One problem however - we would like to get the ball in the air and so, once again, there is a trade off.  When it comes to loft, where possible, I encourage a golfer to go with less loft and show them how to overcome the reduction in launch angle by learning how to hit up on the ball.  The golfer does most of the work here, but a reduction in loft can help with distance.
• The coefficient of restitution (CoR) is the spring like effect the face has when it collides with the golf ball.  As you  might expect the highest CoR on the face is in the center with lower numbers working out from the there.  Golf's governing bodies have made it a rule that this spring like effect cannot be higher than 0.83 and as a result all club companies have made sure that their equipment is right up against the limit.
• The final, and perhaps most interesting, factor that increases the distance your driver makes the ball go is due to roll - no not roll on the ground, but roll on the face.  Roll is the curvature of the face from top to bottom or crown to sole. Manufacturers include roll into the face design in order to create vertical gear effect on hits that are below or above center.  A ball that is struck above center will actually spin less due to gear effect and as a result launch high with low spin - a winning formula for the long ball.  Of course balls hit low on the face will spin more, but they more than likely need a little more air time. Please see Part 2 of this article for a full explanation of gear effect.
• I know of no face design or treatment that increases distance - unless you're working the Chapstick for more than just your lips!

The most efficient a golfer could be with the big stick would be to have a clubhead and shaft that fits them in every way, hit the ball from the inside with an ascending blow and strike the ball slightly above the center of the face and a touch towards the toe.  The reason to favor the toe -  the toe of a driver travels about 14% faster than the heel of the club!

I love this PGATour stat that measures how efficient each player on tour is with the driver.  It quantifies  a player's average distance divided by their average swing speed. It also shows each players average swing speed - an interesting read.

Check back soon to learn about what the driver can do for your accuracy....