Dave Tutelman

Note: In 2010, the USGA adopted new rules about grooves, more limiting than the rules in effect during this controversy.

There have been some postings recently indicating that there are still some folks (including, sad to say, some club pros) that believe that square grooves are illegal. The truth is: 

  1. They aren't.
  2. They never were.

There was a specific technical issue over Ping Eye 2 clubs made between 1985 and 1989. The issue was never square grooves per se, but whether the grooves on this club were .005" too closely spaced. (Folks, that's less than the thickness of a human hair.) Those clubs have been grandfathered, so there are no major clubs that I know (neither pro-line manufacturers nor the well-known component manufacturers) that have a problem with the legality of their grooves. 

So why has there been so much storm and fury over square grooves? The story is an interesting one, so let me waste a little weekend time and write the history. First, a little background: 

  • The USGA is the "governing body" for golf in the USA. They have the authority and responsibility to write and enforce the rules of golf, including equipment rules.
  • The PGA Tour is an association of touring professionals. That is, the Payne Stewarts and John Dalys are the members of the PGA Tour. They hire a "commissioner", to look after their joint interests (that is, to run the tour). That commissioner, for the period in question, was Dean Beman. Basically, the tour players "own" the tour, and set the rules for admission to their private club, as well as exercising control over the tour events.
  • Ping, the club manufacturer, is synonymous with Karsten Solheim. He is the engineer who brought us heel-and-toe weighted putters, oversize aerodynamic wood heads (of real wood, before metalwoods and graphite made them as popular as they are today), and cavity-back irons. None of these innovations, as important as they were, incurred a shred of scandal about legality. (BTW, the company's name isn't Ping, it's Karsten. So they're literally synonymous.)

OK, all set now. Once upon a time...... 

1981: A change in the USGA rules allowed manufacturers to put square grooves in the clubface. This was not intended to affect performance, but rather to enhance manufacturability; casting V-grooves had some problems not shared by square grooves. At the time, cast stainless heads were catching on, and the USGA wanted to encourage the more economical manufacturing process. 

For some reason, only Karsten took advantage of the rule, making legal square-groove Pings from 1981 to 1985 and grabbing considerable market share from the old-line major manufacturers. 

1985: The Pings played well (they did what they were designed to do). But their square grooves were shredding golf-ball covers. Karsten the engineer knew what to do; he rounded the corners of the grooves by maybe .005" -- just enough to remove some "bite" on the balata. Since he changed nothing about the rest of the clubface, that made the flat surfaces between the grooves narrower by .01" -- that is, by .005" along the groove at each edge of the flat.

Now the USGA rules (App II, 4-1e) specify that: 

    "The width of the grooves shall not exceed 0.035" (0.9mm)... The distance between the edges of adjacent grooves must not be less than three times the width of a groove, and not less than 
    0.075" (1.9mm)."

Karsten believed that the width of a vertical-walled groove should be the distance between the vertical walls. If that were the case, then rounding the edges would never have changed either the groove width or the distance between the grooves. For this reason, Karsten didn't even bother to submit the "new" head to the USGA for approval. But apparently there was some controversy on that point.

If you look in the rules today, you will see the 30-degree method for measuring rounded grooves and an accompanying diagram that makes it very clear. And, by that measurement technique, the rounded edges left the grooves officially a tiny bit wider and the distance between them a tiny bit smaller -- enough to be in violation of the rule. So why did I leave them out of the quote above?  I left them out because -- Ta Da! -- they weren't there in 1985. They were added as a result of the Ping brouhaha. 

Because there was no explicit rule for measuring "the distance between the edges" of rounded grooves, there was an honest difference of opinion between Karsten and the USGA. Karsten measured between the vertical walls of the groove. The USGA initially measured the flat surface, then came up with the "30-degree measurement rule" (see Appendix II of your rule book for a picture of this). By Karsten's assumption, the Eye 2 was legal; by the USGA's 30-degree measurements the Eye 2 was .005" out. 

1986-1989: Someone sent the USGA a Ping Eye 2; it was never made public who sent it in. It wasn't Ping; Karsten felt this was a trivial change that didn't affect the measurement, so they didn't send one for approval. The USGA measured it, found it .005" out, and said so. The history that I've read says that the USGA consulted with several manufacturers of V-groove clubs before making its decision, but I suspect that was routine and not conspiratorial. 

At that point, the PGA Tour announced its own rule forbidding square grooves in PGA Tour events. I'm not sure it was the only time it adopted rules at odds with the USGA rules, but this was not a common occurrence if indeed it had ever happened. This difference wasn't noticed immediately, because Pings were the only square-groove club around, and Pings were in trouble with the USGA. So the PGA Tour looked like it was lining up behind the USGA, when in reality it was hiding behind the USGA. 

Note that the USGA had no bone to pick with square grooves; it objected specifically to the spacing between the grooves of the post-1985 Ping Eye 2. So the PGA Tour was clearly working another agenda. What was it? Here are a couple of possibilities: 

  1. The PGA Tour at this time released a study contending that square grooves imparted to the ball a higher spin rate, especially from the rough. This seems to be supported by other studies I've seen. However, the PGA Tour outlawed them because they "changed the character and nature of the game", surely a gross overstatement.
  2. The PGA Tour is, in reality, the touring pros. Individually, each of them is sponsored by equipment manufacturers. At the time, Ping was selling game-improvement clubs to the public, and didn't have many endorsers on the tour; the tour players' endorsements were almost entirely for the traditiional, V-groove club manufacturers who were losing market share to Ping.

So whether you believe that the PGA Tour was a bunch of old fogies trying to ward off technological change (their position) or that they were conspiring with their sponsors against Ping (Ping's position), they don't come across as especially noble. They tried to hide behind the unassailable position of the USGA (whose motives were never questioned; they had to enforce the rule). But the Tour made the mistake of trying to enforce a PGA Tour rule that was totally different from the USGA rule, in intent and -- as we shall see -- in effect. 

1989-1990: Ping was in a tough spot; Karsten's very commercial life was in jeopardy. They sued the USGA and PGA Tour for 100 and 200 megabucks respectively, as compensation for wrongly lost business. 

It took only five months for Karsten and the USGA to reach an out-of-court settlement. The [very reasonable] components of the agreement: 

  • The USGA would clarify the measurement rules to properly describe the measurement of grooves with rounded edges.
  • Karsten would re-tool the Ping clubs to the rules as written.
  • The pre-existing Pings already bought would be grandfathered. This was important to Ping, as it gave confidence to future customers that the company would go to bat for them.

The wording of the settlement included the USGA's agreement that the dispute "was of a technical nature" and not a condemnation of square grooves; moreover, "there was no competitive advantage to a user of the clubs." At that point, the PGA Tour was hung out to dry. Their argument was never the USGA's argument, and they could no longer hide behind the USGA's skirt. 

Just a brief side note: the wording of that last quote was probably intended to say that there was no competitive advantage between the illegal Pings and the Pings with square grooves .005" further apart. No doubt this is true. But if so, it didn't address whether square grooves per se provided a competitive advantage, which was the PGA's contention. For some reason, the Tour never seemed to pick up on this and make an issue of it. 

1990-1993: Still, the Tour didn't settle for another three years. They fought Ping's 200 million dollar suit, even while a court injunction blocked the tour's ban on square grooves and Karsten found a stable of Tour players to sponsor. 

The fact that they settled just 6 days before the Karsten suit was to go to trial leads me to believe that the pros' sponsors were behind the square groove ban. Over my fifty years, I've seen the tactic used over and over again by "the establishment" against an underdog: starve them for business while paying lawyers to delay their getting to court for relief, and hope they die in the interim. If they survive to the trial date, settle quickly (i.e.- concede defeat) and move on. It's just too regular a pattern to be coincidence. 

The settlement was worded in a way to save a little face for the PGA Tour, but not if you read between the lines. It holds both Karsten and the PGA Tour to respect the USGA's primacy in rulemaking. But Karsten agreed to that three years earlier anyway; this only changed the PGA's stance. Anyway, (I hope you're sitting down) in exchange for Karsten agreeing to abide by the USGA rules, the PGA Tour dropped its rule against square grooves. 

So here are the somewhat more detailed answers to the question: "Are square grooves legal?" 

  1. They have been legal since 1981. 
  2. A few square-groove clubs (Ping Eye 2 made between 1985 and 1989) were illegal, but have been grandfathered and may be played legally today. 
  3. Even those clubs were not illegal because of their square grooves, but because of a technicality due to measurement after the edges of the grooves were rounded. 
  4. Square grooves were briefly banned from the PGA tour, due solely to a PGA rule that had nothing to do with the legality of the clubs themselves. 
  5. Depending on which study you believe, square grooves provide no competitive advantage, or they provide slightly higher spin rates from the rough. 

... And, you might well ask, are my sources biased? 

I probably do have a bias. As an engineer and an amateur clubmaker, I have a lot of respect for Karsten Solheim. As an engineer and a citizen, I have a lot of contempt for legal eagles who try to solve commercial and technical problems through either litigation or, worse, legal bullying. Thus I tend to be biased for Karsten and against the PGA Tour. But the USGA? I have been on the technical committee of the regulatory body in another sport (sailboat racing in the Albacore class), and understand and respect the USGA's position; I believe they behaved impeccably through the whole thing, but I hardly believe that's at issue here. 

My sources? 

  • Golfsmith publishes Clubmaker magazine, where I got at least half the facts in this article. Golfsmith undoubtedly sides with Ping; they share a set of commercial interests. I hope I'm a sufficiently astute reader to separate Clubmaker's facts from their opinion, but that's not always possible. 
  • Golf Digest, from which I got most of the rest of the story, takes a lot of ads from equipment manufacturers, the vast majority of them not Ping. Magazines are notoriously beholden to their advertisers (who typically provide more revenue than do sales of the magazine), so I suspect they'd be biased toward the PGA and the traditional manufacturers. 

So I was getting my information from sources on both sides of the dispute. I hope I was able to maintain enough balance of my own to provide an accurate (if not completely unbiased) account. 

Follow-up correspondence:

>From: (Dave Tutelman) 
In article <> (Michael Zimmers) writes: 
>In article <>, >Dave Tutelman <> wrote: 
>>1. The PGA at this time released a study 
>>contending that square grooves 
>> imparted to the ball a higher spin rate, 
>>especially from the rough. 
>Working from memory, an article in Golf Digest 
>showed negligible difference in spin rates from a 
>dry, tight lie, with the difference growing as the 
>grass lengthened and/or became wetter. 
>This may have been just a republication of the PGA 
>article you mention. 

As I responded in Email to Michael, I agreed with his surmise. But, to my amazement, I was able to find the issue in my basement. It was in the December 1986 issue. 

The article involved original research by Golf Digest, with equipment and technical expertise borrowed from Karsten Manufacturing. The conclusion was as Michael recollected. 

  • Square grooves give some negligible spin increase from a dry fairway. 
  • Square grooves give substantial spin increase from wet rough. (Spin rates increased 25%-50%.) 

It wasn't clear from the article whether the square grooves were the sharp (pre-1985) or rounded grooves, but some of the text implies they were the sharp grooves. They admitted that they weren't sure whether the results were due to the shape of the groove or the "roughness" of the knife-sharp edge. They also expressed skepticism about whether the added spin (they assumed their tests were accurate and there was added spin) would be a help or a hindrance to either the pro's game or the high-handicapper's game. 

  • They quoted Tom Kite that he didn't WANT to suck the ball back with any more spin that he could already give it. 
  • They pointed out that the high-handicapper almost always leaves shots short of the the flag when they hit the green. Why would they want more spin? 

This is a 1998 update of an article posted to the Internet by the author in June 1994.