Acer XP Step Cavity Iron

There’s a lot going on with the Acer XP Step Cavity Irons. They begin with a notched sole area that moves the weight toward the heel and toe, where it is needed most. Moment of intertia is increased with an undercut cavity; the step cavity fine tunes this weighting even further.

How many dimples are on a golf ball?

While it varies from model to model, golf balls typically have between 300 and 500 dimples. On average, it seems that balls have around 330 dimples; 336 has been cited as typical.

Dimples typically have a depth of 0.010 inches.

Some models have extraordinary numbers. The Dimplet has 1070 dimples: 656 small ones, and 414 large. By contrast, the new Caesar ball has none—it’s as smooth as a billiard ball.

Dimples however, are necessary for a golf ball’s flight. They have two effects.

First, a bit of physics: Any moving object leaves a wake in the air behind it; wakes in turn create drag, slowing the object. Reducing drag is a key to going faster. That’s why “drafting” works in NASCAR. Having a second car immediately behind the first reduces the wake of the first car, allowing it to go faster. The second car also goes faster because it doesn’t have to push as much air out of the way.

Dimples work to reduce drag by creating microscopic eddies on the surface of the ball. This has the effect of reducing the following wake of air. A smaller wake means less drag.  Although it’s counterintuitive, because of the wake, a smooth ball actually has higher drag.

The dimples also work with spin to create lift. The spinning ball creates higher air pressure on the bottom of the ball than on the top. Like an airplane wing, this forces the ball upward.

Golf balls actually “fly”—they aren’t just shoved through the air.

This principle was discovered by early ball makers, who, when molding gutta percha balls by hand would press random marks into the surface. Later, molds were created that had the impressions built in. Early models, such as the one shown at left had a cross-hatch pattern rather than dimples. The effect, however, was the same.

An Illinois man landed his plane on a golf course in order to get his son to a tennis lesson.

Weird Golf Story of The Week

Earlier this week, the teachers in my building were instructed to attend an in-service called “Love and Logic,” presented by a Dr. Bob Sornson.

It turned out to be three of the most excruciating hours of my life. Worse, we all have to attend part two next week.

Sornson comes across as condescending, vapid and insipid. I found his “insights” into teaching nothing more than vacuous platitudes.

The PGA Tour determines who plays in a tournament through a system of category exemptions. Players in the top category get first crack at any tournament they want. Then players in the next category get an opportunity.

So, for example, the first category is for winners of the PGA or the US Open prior to 1970, or in the last five years (those who won before 1998 have a ten year exemption, so this runs out this year). Once those players have had their chance, the winners of the Players in the last five years are penciled in. Then winners of the Masters, Winners of the Tour Championshiop, winners of WGA events, winners of Tour events in the last five years. And so on.

What this system does preserve “jobs” for those who already are members of the tour. If you win an event, you don’t have to worry about getting into any Tour tournament you want for the next five years. If you pick your tournament chances well, that makes it more likely that you’ll win a second time and extend that exemption. Players who are high on the exemption list also have a much easier time of staying in the top 125 in earnings required to keep their card from year to year.

Conversely, it also makes it difficult for new players to break in. Even players who have sailed through Q School will find (often to their surprise) that they are often shut out of the system. That can make it somewhat difficult to get into the required 15 tournaments—and that much more difficult to stay in the Top 125 in earnings to keep that card.

That explains the oft-lamented lack of new, young talent. They’re shut out by the old-boy system.

Below is the complete and official list of exemptions:

The City of Ann Arbor maintains two public golf courses: Huron Hills and Leslie Park. Leslie Park is billed as the “Championship Course” while Huron Hills is the “entry level course.” Neither is a great course, especially considering the large number of courses (dozens) in the immediate area. Huron Hills does have the distinction, however, of being one of the few “walking only” courses in Michigan.

In recent years, both courses have suffered a decline in play. That may, however, be associated with a general decline in the quality of the fairways and greens. I haven’t played either in more than a year, but reports are that they are in terrible condition.

The City of Ann Arbor has named a committee to study the courses, and what appears to be a money losing proposition for the city. While I never want to see a course disappear, I think the need for two city golf courses is questionable—especially with the many golf courses within a few minutes of city limits.

UnderArmour Heat Gear Glove

Under Armour has branched out of football and workout gear to golf. Their new Heat Gear glove is designed to offer moisture and temperature management.

I have to admit, I was a little confused about the name. “Heat Gear” to me sounds like cold-weather gloves. But after a little research, I found that their cold weather stuff is called “Cold Gear.”

Very original, that.