Frank talk: understanding swingweight and other common equipment terms.

Is it true that a forged blade can shape a shot better than a cast cavity-back?

Mark Yip, Hong Kong 

Cavity-back clubs are designed to minimize the negative effect of off-center hits. They should be more stable at impact so off-center hits will fly close to the intended target. However, if you're working the ball, you don't want straight shots, you want fades or draws. Most tour players use blades because (a) they don't miss the sweet spot, (b) they like the feedback blades provide and (c) they prefer that type of shot to reach tight targets. This is not to say you can't work a ball with a cavity-back iron, but most of us need to concentrate on hitting the ball straight first.

The ideal shaft would be absolutely stiff and extremely light. True? Serge Matovic, Ontario, Canada.

Not necessarily so. A shaft is most efficient when it is able to bend and then unbend (and release all that stored energy) just before impact. An extremely stiff shaft is just like an extremely stiff fly-fishing rod: No feel and difficult to manipulate. Hard-swinging pros can get an X-flex shaft bending like most of us get an R-flex shaft bending. Without that bending, we aren't able to take advantage of the shaft's design, and our potential.

What is swingweight? Tony Falvo, Georgetown, Tex.

Swingweight is a static measurement, nothing to do with swinging the club. Roughly speaking, it's a measure of how the weight of a club is distributed. Imagine balancing a club on a knife-edge (or "fulcrum") at a point 14 inches from its butt end. To make it balance, you'd have to add some weight to the butt end, right? The swingweight is basically a reflection of the amount of weight you would have to add to the end of the club to make it balance on such a fulcrum. Using an arbitrary conversion table, the numbers are converted to an alphanumeric code, such as C3, DS, E2 and so forth. The lightest swingweight a club could have using this conversion system is A0; the heaviest is F9. The average is about D0 to D2. This is called the Lorythmic system and is used by most manufacturers. (A clubmaker called Robert Adams invented the swingweight scale in the 1920s and successfully used it to "match" clubs for players like Bobby Jones and Francis Ouimet.) Because it's a simple static balance, swingweight is not the dynamic measurement its name implies. But if used in concert with the overall weight of the club, it does give some indication of the dynamic feel or balance of the club.

Is there a standard range of lofts for woods? My 5-wood is 21 degrees, but a 7-wood I'm looking to buy is 22 degrees. Steve Johnson, New Glarus, Wis.

Unfortunately, today's equipment lacks standards. There should be 4 or 5 degrees difference in loft between the 5- and 7-wood. Most 5-woods have a loft of about 21 degrees. The 7-wood is a good choice, but by adding one or two hybrid clubs you can give up your 3- and 4-irons. The entire set makeup is changing, with more wedges being added and with hybrids and higher-lofted woods replacing some irons. Generally, the fairway woods with the same loft as the hybrid seem to get the ball up a little more than the hybrid but with less of a boring flight. Regardless of which way you decide to go, woods and hybrids are easier to hit than longer irons.

Frank Thomas, technical director of the USGA from 1974-2000, is Golf Digest's Chief Technical Advisor. E-mail him at equipment @golfdigest.com.