For the minority who are prepared to swallow the truth, an understanding of the five standards applied to golf balls is essential:

1.              Weight – The ball can’t be heavier than 1.62 ounces.  A ball a little heavier would probably travel a little longer.

2.              Size – The ball can’t be smaller than 1.68 inches in diameter.  A smaller ball might be advantageous – especially when played into the wind.  The test used in the USGA lab calls for balls to be tested at 75 degrees Fahrenheit after preparation in an incubator.  It’s such a sensitive test that a five-degree drop in temperature can make the difference between pass and fail because the ball contracts as it cools.

3.              Initial Velocity – The standard is expressed as 250 feet per second, with a 2% tolerance, on the USGA apparatus, which features a metal flywheel as a striker.  The tolerance is a scientific message saying that the device might fluctuate by as much as five feet per second.  Manufacturers are confident that the performance is much better than the 2% tolerance indicates.  Many tend to build right up to 255 feet per second – the standard plus the tolerance.  Occasionally a brand will fall over the line – ever so slightly  - and is stricken from the USGA list.

4.              Spherical Symmetry – This test was introduced in 1983 following development of a ball with an asymmetrical dimpling arrangement advertised as being a preventer of extreme hooks and slices.  A symmetrical ball will do what it’s supposed to do – swerve off line when struck improperly.  It was on this principle and to introduce the symmetry standard that the USGA prevailed.

5.              Overall Distance – Introduced in 1976, this vital test is performed by robot – the celebrated Iron Byron – which hits balls into a fairway outside the USGA Research and Test Center.  Iron Byron used a conventional wooden driver with a loft angle of 11 degrees.  At the instant of impact his club is traveling 109 miles per hour, about the speed of a long-hitting touring pro.  A calibration ball is launched at nine degrees.  The clubhead is laminated, not persimmon, because it simply doesn’t matter – in terms of distance.  About every 4,000 hits a shaft snaps, which makes for a lively few seconds in the Test Center as the clubhead ricochets off a wall or ceiling.

For a ball to flunk the overall distance test, it would have to travel 296.8 yeards – carry plus roll – under controlled conditions.  This is stated in the specifications as a maximum of 280 yards plus a tolerance of 6%.  When the Overall Distance Standard was established in 1976 it was with the understanding that no ball then in existence or in the pipeline of research would fail.  Thus, manufacturers were given a kind of innovative tolerance amounting to an improvement on the order of 4%.  That gap has just about been closed.

In other words, the USGA now takes the position that golf balls, when struck by a mechanical golfer designed to replicate what happens in real life, are never to go more than a few yards longer than today’s balls.  It’s a shame the USGA couldn’t have said that 30 or 50 years ago, but it’s useful to be able to say it today.

Note that there is a modifier in the USGA’s level of confidence.  It applies to drivers.  A variety of factors, including dimpling configuration and weight distribution, causes balls to perform differently at different launch angles.

*Adapted from 1987 U.S. Open Program.