Welcome

May PGI Contest

You owe it to your game to make the best of your abilities; become " Master of Your Own Game". Stand out and improve, without hitting any balls!!

Here's to a long lasting life of great golf!

My latest study is finished. See some of the details of the reports HERE.

A Brief Message        May 3/04

• Ken here from Probable Golf Instruction. In my last newsletter, I explained how golf ball technology changes have affected distance. Review the newsletter here.
  
• In this issue, I'll continue the discussion with emphasis on backspin effects.
  
• About 5 weeks ago, I received a copy of Swing Machine Golf. The author, Paul Wilson, uses a unique teaching method with his students. He has been featured a number of times on The Golf Channel. He models his teaching swing after the machine, Iron Byron. His emphasis is on simplicity. I think it is an excellent book (one of the best I've read). I think you'd be impressed, too. Take a look at it here, Swing Machine Golf
  
• Have you played any matches yet? Do you find you are at a real disadvantage on some holes because you don't get a shot or have to give away a shot? It could be your holes' difficulty rankings do no reflect reality of how golfers play them. Find out your course's true hole rankings here.

Distance & Technology Part 7: Golf Ball Spin Distance

If you'd like one on one explanations about the topic, sign up for the PGI Member Select Club and I'll answer all your questions in a prompt, thorough fashion. Now on to this week's topic.

     If you've been a Probable Golfer long, you know that most of the analysis that I do is using a golf ball trajectory computer program that I have written to simulate golf ball flight. The most difficult things to factor in are the changing drag and lift forces that occur on the ball. Both are dependent on ball speed and backspin. They are ever changing. I have accomplished this task by using a spreadsheet. My model agrees very well with experimental results. To see more, go here.

     With my computer model, I can change certain quantities and keep others constant. In this case, I varied the amount of backspin on the ball (simulating different types of balls: low spin, high spin, etc) and calculated carry and total distance for different driver speeds. The results are tabulated below. The values assume a 10 degree lofted driver and a 12 degree launch angle.

     For the 80 mph clubhead speed, total distance is optimized with a high backspin of about 4000 rpm while carry distance is optimized at an even higher backspin. For 100 mph, carry is optimized at about 3800 rpm and total distance at 3300 rpm. for 120 mph, carry is optimized at 3000 rpm and total distance at 2400 rpm. Basically, the higher your clubhead speed, the lower spin you want, thus you should be playing a low spin ball. A low clubhead speed player should be playing with a high spin ball (as has been discussed in previous newsletters, a low clubhead speed player should be playing with a high loft driver).

     It should be noted that realistic backspin values for a Driver are in the range of 2500 to 3500 rpm, the most significant determiner being the loft of the club. Matching this range with the table values above, it can be observed that there is really no significant difference in distances. You cannot really change significantly your driver distance by using ball manufacturers' "low spin" balls or "high spin" balls. What is more important is the correct loft of the driver to match your swing speed (discussed in a previous newsletter).

     What about when playing in the wind? Take a look at the computed results for the 100 mph clubhead speed with a 11 mph wind. Note that the effects of backspin are a little more significant. You might consider using a low spin ball for hitting into the wind and a high spin ball for hitting with the wind.

Backspin (rpm)	Club speed 100 mph 11 mph head wind		Club speed 100 mph No wind		Club speed 100 mph 11 mph tail wind
1200	195	226	199	241	200	253
1500			205	243
1800	203	228	208	245	211	259
2100			213	247
2400	207	229	216	248	219	263
2700			218	249
3000	208	226	220	249	226	267
3300			222	250
3600	206	222	223	249	231	269
3900			223	248
4200	201	215	222	246	233	269

Purchase my Longest Golf Ball Report (over 230 sold so far) in which I statistically analyze distances of over 70 different golf balls with differing constructions. The balls were hit using a mechanical hitting machine.

Take a look at the results of Equip2Golf.com, an independent golf testing company. They have tested many of the new golf balls using golfers and launch monitor equipment. Below is a sample of their results.

Ken Tannar

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