Adaption Agents

In its first direct response to the distance explosion that detonated more than a decade ago at the game's highest level, the USGA, after much deliberation and many millions spent in research, has chosen to -- drum roll, please -- reduce the width, depth and sharpness of grooves on iron clubs.

Not by modifying the golf ball, or the size of driver heads, both of which would be a more direct way of slowing down the pro game. Rather the more indirect route of reducing the amount of spin that could be applied from certain lies, and then banking on a projected chain reaction of events to impede the further spread of the power game. Ta-da.

Although the modification officially takes effect Jan. 1, it has left the key principals -- players, equipment manufacturers and course set-up staffs -- wondering just what the net effect is going to be. Meanwhile, most golf fans still aren't sure what all the fuss is about.

So first, a clarification. Grooves on irons exist to create backspin that assists in control. Until 1984 uniform tooling and rules that regulated spacing produced a relatively narrow groove that was cut in a "V" shape from top to bottom. That year, Ping founder Karsten Solheim, under what he contended were the same parameters, created grooves that were more U-shaped and wider. It was soon found that Ping's grooves -- which came to be known as square grooves -- imparted more spin than conventional irons, particularly from the rough.

The reason is the same one that applies to rain tires. The bigger grooves in the tire displace more water, allowing the rubber to make more contact with the asphalt and thus have better traction. In the same way, grooves with more volume and less space between them take in more grass and moisture, leaving less debris between the steel surface and the cover of the ball, allowing more backspin and control.

On the PGA Tour square grooves had an important role in making the general style of play more aggressive. Because they made it easier to hit a controlled shot from rough -- both from off the fairway and around the green -- players began to worry less about placing their drives in the fairway and were more concerned with hitting as little club as possible for their approach. They also began firing at more pins, because even if they missed on the so-called "short side," the spin from square grooves on their wedges made scrambling easier. The style became so prevalent among top players such as Vijay Singh and Phil Mickelson that it got its own name -- Bomb and Gouge.

The USGA's new parameters on grooves for clubs of more than 25 degrees (basically 5-iron on up) allow for more volume than the original V-groove, but about 40 percent less than square grooves. They also mandate a more rounded radius on the edge of the groove than is currently the norm. The intent is to reduce the control from rough and thus reward players who find the fairway more often. Theoretically, a wider array of skills will be required to judge and execute shots from difficult lies from off the fairway and from taller grass around the green.

While many players have favored V-grooves in their irons through the 9-iron, virtually all have long played square grooves in their wedges. Those who had square grooves throughout the bag will presumably have a bigger adjustment to the new rules. They will have to deal with the possibility of more so-called "flyers" or "jumpers" -- iron shots hit from rough that carry little spin and fly farther than a shot from the fairway and land harder. Everyone will have to adjust to less spin and its consequences with the wedges.

How much difference will it make? Estimates range from dramatic to less than zero. I thought Steve Stricker nicely phrased the most sensible projection:

"It's not a huge difference, but enough to make a difference."

On the brink of a new season, no one knows for sure what the effect will be. Based on conversations with players, caddies and various wise heads from equipment companies and ruling bodies, here is what I think is going to happen.

1. Driving distance will go down: Some might shift to a softer, spinnier ball that could cost as much as 10 yards. With more incentive to be in the fairway, players will hit more 3-woods and cut drivers. This year the distance leader was Robert Garrigus at 312 yards. Look for the leader to drop to less than 310 yards. The average was 287.9 yards. The number has done almost nothing but go up since stats began being kept. I think in 2010 there's a good chance it go down by more than half a yard.

2. Driving accuracy percentage will go up: The combination of softer balls and incentive to be in the fairway will change things a bit. Players who are straight already, such as perennial category stalwart Tim Clark, probably won't play differently. But most B&Gers will probably pull back a bit to be in the fairway more. The tour's fairways-hit average of 62.91 percent in 2009 was one of the lowest in history. Chances are good that will remain a landmark of the B&G era.

3. Percentage of greens hit will go down: Flyers, and the doubt raised by the increased possibility of a flyer -- especially with middle and short irons -- will mean more greens missed. Reduced spin from the fairway and especially from the rough will mean more balls rolling to the back fringe. Players are reporting that reduced grab from the new grooves is causing balls to climb up the face, thus launching higher and traveling as much as five yards a club shorter. Lofts may get jacked a bit, but hitting effectively longer clubs into the greens will take its toll in accuracy. On the other hand, more players may settle for the middle of a green rather than shoot at pins because the penalty for short-siding will be greater. This year the category leader was John Senden at 70.89, the lowest percentage for a leader ever recorded. Might 2010 be the year no one hits 70 percent of the greens? As for the tour average of 64.7, it too will drop.