Dave Tutelman --
August 19, 2007
Updated November 21, 2015
Updated October 4, 2016
Here is my latest (2016) take on
single-length iron sets. This time, I restructured the article,
starting with the prinicples of single-length clubs and finishing with
a separate page of simulation studies of products on the market
is a discussion of the yardage gaps for a set of irons. This is crucial
understanding an important difference between conventional and
single-length irons, and is an important consideration for conventional
irons as well.
recurring theme in club design is, "Why must irons be of
different lengths? What is wrong with having all the irons the same
length?" From time to time, I have looked at this question from
engineering point of view. This is the fourth time I
gone through the study in almost 20 years. Here is a synopsis of the
I sharpened my tools to be able to update the article without
too much effort any time a new set came out. And I reorganized the
article into two pages:
study -- mid-to-late 1990s. It is still around,
more or less, in my tutorial on golf clubs.
look -- 2007. I was asked by Bill Wade if there is
anything new on the subject. What I found was a company that makes sets
of these clubs (1
Iron Golf) and another that sells heads designed for such
look -- 2015.
That year, Bryson DeChambeau won the US Amateur and the NCAA individual
honors using a single-length
set, then turned pro and finished well up the leaderboard in his first
few tournaments. He generated a lot of new curiousity about
look -- 2016.
Probably because of interest generated by Bryson DeChambeau's success,
a number of companies introduced
single-length sets into their catalog. A few manufacturers and several
custom clubfitters got on my case about evaluating the new products. So
I did. Here it is.
- This page, which presents the criteria I think are
important in comparing the offerings, paying special attention to
yardages and yardage gaps.
- The next
page, which evaluates the offerings I have seen, according to
the criteria on the first page.
Why single-length clubs?
a better question would be, "Why is each club a different length?"
After all, with
a movement as complex as a golf swing, where a clubhead inaccuracy of
an inch or a couple of degrees makes a big difference in result, why
complicate things unnecessarily? Let's look at a few reasons that
single-length clubs uncomplicate things for both the golfer and the
- The golfer can use the same swing with
the same swing plane. No need to flatten the plane a few degrees for
the long irons or get over the ball more for wedge shots. No need to
worry about different ball positions for different clubs. Just set up
the same and swing the same.
- The clubfitter does not have to
worry about heft matching. Swingweight vs moment of inertia? Not an
interesting question. If the heads are the same weight club-to-club,
the shafts are the same weight, and the clubs are the same length, then
the entire set of clubs will be heft-matched by any criterion
to apply. Swingweight, moment of inertia, total weight, or anything
else you care to use. You like fourth moment? I can't imagine why, but
- Same for flex matching. If you as a
clubfitter frequency-match the clubs you make, you no longer have to
decide what frequency slope to use. The clubs are all the same length
and heft, so make them all the same frequency. End of story. Similarly
simplified if you use a deflection measurement to match flex. No matter
which deflection measure you use, having all the clubs the same length
makes it easier to match them.
Well then, why not
single length clubs?
just saw a cogent set of reasons for single-length clubs. The arguments
against are more subtle, and perhaps less important -- or not.
let's continue this investigation under the assumption that
single-length irons hold an advantage for at least some golfers, and
perhaps most or all.
(Cue the "Fiddler on the Roof" score.) Golf is a traditional game. If
nothing else, an awful lot of golfers have an investment of both money
experience in traditional equipment and technique. Breaking away may
take more than just demonstrated superiority; it may take a new
generation without the baggage.
- Range! By that, we mean the
difference in distance between the longest-hitting and shortest-hitting
club in the set. A conventional-length set with the same lofts has a
bigger range than a single-length set. The reasons for this, and
what might be done about it, are the subject of much technical
discussion in this article.
- Accuracy -- maybe. It is distinctly
possible that the major advantage of single length for most golfers is
not "one swing for all clubs". Perhaps it is as simple as
lesser-skilled golfers finding it hard to effectively use an iron
longer than a 7-iron or so. In that case, shortening the longer irons
single-length sets) may be a big win. But continuing with single
length for clubs shorter than a 7-iron may be a disservice to the
golfer. If the golfer really is more reliable and more accurate with
shorter clubs, then we should let the higher-numbered clubs continue in
a conventional length progression.
- Biomechanics -- maybe. I
don't know of any serious biomechanical study to evaluate the
effectiveness of single-length sets. We might learn something
surprising from such a study. Let me speculate wildly here. Suppose we
find that a flatter plane results in a freer swing and more clubhead
speed. That would suggest that golfers of sufficient skill should
continue to use longer clubs where distance is the main criterion
(3-iron) and shorter clubs where accuracy is (9-iron, wedges).
Before we leave
discussion of "why single-length clubs", let's consider the golfer that
has made it a hot topic. Face it, the idea has been around for decades,
and a few commercial offerings have been around for years without
a big dent in the market.
Why now? Bryson DeChambeau! In a very short space of time, he:
sort of performance draws attention. And much of that attention was
focused on his clubs. He had just graduated from SMU with a major in
physics, and his clubs are very non-standard. He and Edel (a high-end
golf club company) designed them specifically for his swing. And the
irons are a single-length set.
- Won the NCAA individual title.
- Won the US Amateur title.
- As an amateur, finished tied-21 at The Masters and easily
- The following week, in his first tournament as a
professional, he was on the leaderboard all week and finished tied for
Everybody noticed the single-length
nature of his clubs. Announcers were talking about it endlessly, and
the magazines mentioned it every time they mentioned him. So a lot of
people were thinking, "Maybe he's so good because of the single-length
irons. Hey, he's very smart in physics (his nickname on Tour is "Mad
Scientist"), so he has obviously thought this out. Maybe I would be a
lot better if I had a single-length set." Before you get too excited
about this, you should be aware that his clubs are very different in
other ways as well. He uses a Mo Norman style of swing (which is
probably quite different from what you learned), and his irons
are built with:
So single-length irons might be a good idea indeed. But it's hard to
say DeChambeau proves it, because there are so many unique
things about his clubs.
- All the same length. (Well, we already knew that.)
- The length of a 6-iron. (That's perhaps a tad too long for
most lesser-skilled golfers' single-length clubs.)
- A Jumbo-Max grip. (For a rather different use of the hands
than most golfers.)
very upright lie angle. (A typical 6-iron lie is 62°. Bryson's irons
are 73°. If you put your normal swing on an iron this upright, you
would hit a 150yd shot to
the left by 15-20 yards.)
Bear in mind that this study is done using computer modeling. I do not
have the resources to do a lot of testing with real clubs.
biggest reason you need a special set of clubheads for single-length
irons is length and weight. If you bought a conventional set of
clubheads and built a single-length set from them, the swingweight
would be all over the place. (And if you prefer MOI-matching to
swingweight-matching, the MOI would be all over the place.) Numbers,
if you want to build a single-length set, you are going to need heads
designed for the purpose. Let's look at the heads on the market in that
regard. All the offerings design their heads in the 270-275g range. The
usual (conventional-length) 7-iron head is 270g, so these were intended
to be the length of a 7-iron or slightly shorter. If you
want to build them longer or shorter than that, you face the usual
choices any custom clubmaker has to deal with.
- Suppose you built a single-length (37") set from
components that were intended, when built to conventional lengths, to
give a nice D-0 swingweight across the board. You would find that your
3-iron was a B-9.5 and your PW an E-2.5. That is because the 3-iron
head was made to balance a rather long club, so the head is lighter
than the others. And the converse for the PW.
- OK then, how
about fixing it with tip weights or lead tape? In order to get them to
the same swingweight, it would have to be a very heavy E-2.5, because
they would all be the weight of the heaviest head, the PW.
then, suppose we make the clubs only 35" long, the length of a
normal PW? Then we can add weight to the other heads and still have a
good swingweight. We could use tip weights or lead tape. The problem is
that you would need to add a lot of weight as the clubs got longer.
You'd need about 50g for the 3-iron. Even if you only went to a 5-iron,
that is still 35g needed to be as heavy as the PW. I have
seen tip weights over 10 grams, so you'd still need lead tape. A lot of lead tape!
40 grams of lead tape is over 4 feet long!
Other simple stuff
are several things that differ from model to model of single-length
iron head. Some of them are the same things you would consider in
selecting a conventional set of irons. These include:
The most substantial technical issues surrounding a
single-length set of irons is the number of clubs and their lofts. The
output of these specifications is range
and that is what we will spend some time on now.
- What it looks
If you don't like the looks, you've put something into your head that
is almost guaranteed to make it less suitable for you. But that's
personal; I can't help you there.
- Head style:
blade, cavity, or something in between. The single-length products on
the market (as of October 2016, at least) are being sold as game
improvement clubs -- and that is almost certainly the market that will
tend to buy them. As such, they are all cavity-back models. If you feel
you must have a blade, you will have to stick to a conventional-length
set. (A bit later in 2016, Cobra introduced two single-length models,
including a forged "players club".)
surprise, the offsets on most of these irons (again, as of October
more like players' clubs than game improvement. Most are a constant
offset of about 3mm, but a few offering are progressive with the
low-lofted irons at 5 or 6mm. (For comparison, most conventional game
improvement irons have an
offset in the 6-8mm range in the longer irons.)
- Lie angle:
All the offerings are in the range of 62.5° to 63.5°. This
shade high, maybe a half degree or so. Looking over conventional iron
specs, the 7-iron is typically 62°-62.5°, and an 8-iron maybe a degree
more than that. So we're not too far from what the industry considers a
or slightly shorter. And note that game improvement clubs tend
have more upright lie angles than players' clubs. (An upright
is a slight counter to a slice.) So close to what we would expect.
|The range of a set of clubs is the difference in
distance between the longest-hitting and shortest-hitting clubs. It's
the range of yardages you can cover with a full swing. And, unless you
mess around with loft lineup and other features, you will get more
conventional irons than single-length irons. We'll see it
quantitatively below, but let's just state the general reason first.
distance from club to club is based on two important variables: loft
and clubhead speed. Lower loft gives greater distance. Higher clubhead
speed gives greater distance. And, for a properly-designed and -built
set of irons, a longer club delivers greater head speed.
get a feel for how range changes. Here are two sets of irons. One is a
single-length set, with all that implies, and the other a conventional
set. The only thing that we have held the same between the two sets is
the loft lineup; both sets have the same loft in all the corresponding
|Range of set
Some choices I have made with these two sets:
have chosen a loft lineup with a 4° gap from club to club. This was a
standard lineup in the late 1980s through mid '90s, but is no longer
today. I'll go into more detail below, when I talk about the "loft wars".
But we want to start our analysis with this uniform loft gap, because
it teaches us things about designing iron sets.
- I have chosen
the 7-iron as a "pivot club" (highlighted as the orange row in the
table). That is, the constant-length set has all
clubs with the measurements of the 7-iron from the conventional set.
Well, all the measurements except loft; that is kept from
corresponding club to corresponding club.
Another way to look at it is a graph, so here is a graph.
I am using for graphing has numerical scales, so the PW will be a
10-iron on the graph, and a GW will be an 11-iron.)
There is not a lot of range difference between the sets, less than 10
yards out of a 100-yard range. But the range difference is there. I saw
a video review recently of a single-length iron product. The reviewer,
Mark Crossfield, noted the difference in range; he said it was a small
difference, and he would probably find them equal if he ran the test
again. Right on the first count; the difference is small. On the second
might find them equal the second time. He's a professional
golfer and can instinctively do what is necessary to make the shot. But
the chances are you
won't be able to equalize the ranges. And it's a bad idea
to even try. The point of single-length clubs is to make all your
swings the same. If you do that, there
will be a range difference.
We can take a sharper look at this -- and learn a lot about how club
length and loft affect distance -- if instead of looking at the entire
range we look at the yardage gaps from club to club. Let's do that.
need a spread -- a pattern -- of distances that various clubs will
travel. When a custom clubfitter bends the lofts to create that
pattern, the process is called "gapping"; it generates a set of yardage gaps from
each club to the next. There are a couple of reasons to spend a lot of
time on it here:
- The yardage
gap lineup is one of the main properties I use to compare
the single-length sets on the next page. If you hope to improve your
scoring with a single-length set, pay particular attention to the gap
pattern. A poor set of gaps for your game will hurt your scoring at
least as much as a single swing would help.
- The gap discussion
is equally important for conventional-length iron sets. I'm
tell the whole story here, both single-length and conventional-length,
so I have it to refer to in the future.
|Let's look at the two sets we evaluated above,
and plot the gaps instead of the actual distances.
the "4" gap is the gap between the 3- and 4-irons. The "7" gap is the
gap between the 6- and 7-irons. Etc.
we look at the gap curves, we see that the conventional set has bigger
gaps than the single-length set for most of the gaps. The gap is two
yards for the longer irons, and shrinks (even overlaps in one place)
for the shorter clubs. A lot of the "jagginess" of the curves is due to
the granularity of the computer output. Specifically, yardages are in
full yards, no fractional yards. Since we are taking differences here,
just rounding to the nearest yard can make the curves look pretty
jagged. But the trend is clear; the gaps are bigger for the
So it should not be surprising that the range is greater as well, since
the range is the sum of all the gaps.
As long as we're getting a little
mathematical about it, let me make
another observation. (Don't
worry if you don't get it. It's not that important, just
an interesting way to think about the curves. If you don't have any
feel for calculus, skip this note altogether.
) The gap
curve is roughly the negative slope of the distance
curve. That would make it the derivative
of the distance curve (times minus one, of course). Looking at this
relationship a little further,
that makes the distance curve the integral of the gap curve. So we can
get the distance range from the area under the gap curve.
you want to take this literally and actually do the integration, here
are a few things you'll have to do that weren't in my offhand
- Use the negative of the gap curve, because it is
the negative of the slope. Alternatively, start at the right and
integrate right to left. You're essentially integrating dy/d(-x).
- Apply a hefty initial condition to the integration,
namely the distance for the club where you are starting.
approach to gapping
have looked at the gaps for many sets of clubs, and here is what I
found. The typical gap for a conventional set is 85% to 90% due to
loft, and only 10%-15% due to clubhead speed. So if we want the gaps
for a single-length set to be the same as the gaps for the conventional
set, we want to increase the loft difference by 10%-15% to make up for
the clubhead speed we're not getting by not adding length.
far, we have been using a simple loft lineup, with a 4° loft gap
between clubs. If we want to maintain the same yardage gaps for a
single-length set as a conventional set, we should
have a 4.5° loft increment
from club to club. That is, we add 12.5% (halfway between 10 and 15) to
the 4° loft. Let's test this assertion. We will repeat the graphs, with
this modification to the SL set.
the range is the same 97 yards for both sets. And both sets appear to
track pretty closely, except that the SL set gets lower yardage at both
high and low end of the set (the 3-iron, 9-iron, and PW). The gap graph
for the SL set is more jagged than before, but the important
So #1 says that our correction to a 4.5° loft gap works, at least
mostly. But let's see if we can understand more about #2. This
will be very educational!
- The net area between the gap curves is
just about zero; the red curve is as much below the blue as it is
above. That is why the ranges are equal.
- There is a much smaller gap between the 3-iron and
4-iron: only 8 yards, when the next lowest gap is 14 yards.
I'll start by giving away the answer: it takes a lot of clubhead speed
to get full distance out of a low-lofted iron.
We all know that slower swingers need more loft in their drivers. Not
only do the get less distance than those with higher clubhead speed,
but they need more loft to get their own maximum distance. Well, the
thing occurs with irons, just at a higher loft and lower clubhead
speed. (Some day, I'll have to take a good look at why metalwoods and
even hybrids seems to get more distance than irons of the same loft.
But I digress.)
Those are just words so far. But a few graphs will make it more -- well
-- graphic. Let's see what the distances and gaps are for a
single-length set of irons at various clubhead speeds. I've added a
2-iron to the set, with a 16° loft, because it makes the effect much
more visible -- though it is clearly there even if the lowest loft is a
20° 3-iron. We show four clubhead speeds, from 70mph (typical for a
senior with a middle iron) to 100mph (probably middle of the Tour pros
Take a look at the difference in shape of the curves.
At 100mph (pro speeds), the distance curve is nearly a straight line
visually, and if anything it is curved upwards. A look at the gaps
confirms this; from the 3-iron (the "4 gap") through the PW, "longer"
irons have a larger gap. When we realize that the gap is an
approximation of the slope of the distance plot, distance must curve
upward. It isn't until we get to the 2-iron (the "3" gap) that we see a
falloff in gap -- and not a huge one; the 2-iron is still a useful tool
for the pro.
But as clubhead speed drops, so does the gap for the lower-lofted
clubs. The 3-iron loses relative distance at 90mph. (That is,
its gap to the 4-iron shrinks.) By the time you get to 70mph, the gap
starts shrinking with the 5- or 6-iron. By the time you get to the
2-iron, the gap is negative; you lose actual distance, not just
relative distance, compared with the 3-iron. And even the 3-iron
doesn't earn its place in the bag; it only gives 4 more yards than the
You might well ask, "But that was a single-length set. What would
happen if it were conventional length?" Valid question. The answer is,
"Same thing, but not as much of it." With a conventional set, you won't
get the same clubhead speed across the set; the longer clubs with have
a slightly higher clubhead speed. So the longer clubs will get a little
more distance. You won't see quite as much 3-iron droop. But it sure
will be there. Look at the first graph we
did for gaps; the 3-iron droop is clearly visible for both
the conventional and single-length set. The droop is nearly the same;
rounding to the nearest yard makes them indistinguishable.
We will get back to droop in a moment. But first, I'd like to dwell a
bit on what the shape of the gap curve ought to be.
professionals know exactly how far they hit each club in their bag with
a "stock" swing. You should too, if you want to get the most
out of your game. But most of us, myself included, approximate those
distances to a round number, a 5- or 10-yard distance. If your distance
control is only within 5 or 10 yards, this vagueness is appropriate --
certainly makes it easy to remember the distances.
if your skill does justice to knowing the exact distance, it isn't as
easy to remember where you hit each club, especially since skilled
players can use different swings for each club. Some Tour players
need a written yardage chart to keep track of where they hit various
clubs with their various swings.
Bryson DeChambeau (whose single-length irons were the motivation for
new interest in the concept, which itself is motivation for this
article) has a
particularly complex chart. He and his caddy consult it on almost every
shot. Here is a picture of Charlie Rymer trying to explain DeChambeau's
chart to the Golf Channel audience. The chart certainly argues for
and ease of memorization.
and ease of memorization strongly suggest that all the gaps should be
the same. For instance, consider the set we've been working with:
single-length set with 3-iron through PW and a range of 90 yards. There
are 8 clubs in the set, so there are 7 gaps. If we divide the 90-yard
range into 7 equal parts, each part is just about 13 yards. Well,
actually 12.86 yards. If they were all 13 yards, the range would be 91
yards. Close enough; let's keep it simple. We design the lofts to give
us uniform gaps of 13 yards each. If we ever forget one of the club
distances, we can figure it out quickly by adding or subtracting 13
yards from an adjacent club in the set.
So a simple, easy-to-remember distance chart comes from a constant-gap
But is that the best we can do? If we are willing to carry around a
chart, there might be a better way. Consider this:
Here is a pair of graphs that compares a constant-gap set to a
don't have the same distance control in yards for all our clubs. The
further the club can hit the ball, the more yards it is likely to be
off the mark.
- That means that, with a constant gap, we might have a
very clear choice which
club to use for a short iron shot, but a long iron shot may have a
distance uncertainty larger than our gaps.
- So another design for gapping might be "proportional
gapping" where the gap is proportional to the distance. This makes
choosing a club
more clear, because the gap gets bigger as the uncertainty gets bigger.
is easy to see that the proportional gaps are bigger for the
longer-hitting clubs and smaller for the shorter-hitting. But the total
range is the same 90 yards, from 100yd with a PW to 190yd with a
3-iron. The result is that most of the clubs in the proportional-gap
set hit a few yards shorter than the constant-gap set. Only the clubs
at the ends of the range (3-iron and PW) hit the same distance. In the
middle of the set, the 6-irons are different by 7 yards.
have two different gapping strategies: constant gap for simplicity and
memorizability, and proportional gap for optimized play at the expense
of considerable memorization or carrying a chart. Either could make
sense, depending on how you want to play and think on the golf course.
Personally, I'm happy enough not to optimize, just keep things simple
with a constant gap. Over-analyzing on the golf course is one of my
faults anyway; I don't want to make things worse.
Loft wars and
the late 1990s, golf club companies discovered a new way to
competitively advertise their clubs: "You can hit your irons farther
than your friends can hit theirs!" (My impression at the time was that
Cobra led the way on that, but all the OEMs were guilty eventually.)
They accomplished this through stronger lofts. After a few annual
product cycles, the specs of a 7-iron were those of an older 6-iron.
Yes, the new 7-iron did hit the ball farther -- more like a 6-iron. And
yes, there was an obvious reason for that.
were a few unfortunate consequences. (Well, unfortunate for the golfer.
They were neutral or even favorable for the club
Here is a table of lofts for a typical 2016 set of irons. It happens to
be the Callaway Steelhead XR,
but the other OEMs are pretty similar. I have included in
the table the loft gaps from each to the next. And the first column is
the "tradtional" loft lineup from the early 1990s, the one we have been
using as our reference lineup. Its loft gap is a constant 4° across the
- You can only make the 3-iron loft so strong before
golfers don't get any advantage out of it. (See the section on 3-iron droop
above.) So the manufacturers squeezed the lofts together at the long
end of the set, so the lowest loft would still be hittable.
can only make the sand wedge loft so strong before golfers can't use it
for getting out of a bunker or hitting a high, soft pitch. The result
was a huge gap (more than 10°) between the PW and the SW. The
manufacturers solved the problem by introducing the gap wedge. Side
benefit -- for them,
not for you -- was the revenue opportunity of selling you
another club as an integral part of the set.
|Let's see what this new loft lineup looks like in terms
of distance gap.
But, even before we do the exercise, it does not look promising. It is
I ran through the calculations, and the blue graph is
what it looks like with a conventional-length set. Points worth noting:
- Not a constant gap.
- Deviating from a constant gap in the wrong direction
-- away from a proportional gap.
- And we can expect 3-iron droop to make it even worse.
case you were wondering, going to a single-length set with these lofts
would be even
worse, because you don't get the clubhead speed difference to temper
the undesirable characteristics.
has a really good range: 107 yards, from a GW of 97 to a 3-iron of 204.
(That is compared with a 97 yard range for the conventional-length set
we have been looking at.) But remember, we have an extra club in the
set -- the gap wedge. It would be a big disappointment if the extra
did not result in a larger range.
- The shorter irons, down to the 6-iron, look fine. The
gaps are 15-17 yards, a generous and constant gap.
- But going to longer irons gives a huge droop. The
gaps 3-4, 4-5, and 5-6 are between 8 and 11 yards.
- Note that this is worse than a constant gap; it is
significantly sloped in the opposite direction from a proportional gap.
don't think the big hitter gets off easy here. A droopy loft pattern
guarantees a droopy gap pattern, no matter how much clubhead speed you
Before we leave the "modern" loft lineup, I'd like to
point out that the set could
be modified to have the same range big and a really good constant gap
All we would have to do is combine the 4- and 5-irons into a single
club with a distance of 190 yards. We could do it with a loft of 22.5°.
That is the dotted
in the graph. It would give two gaps of 14 yards
each, which is in the same
ballpark as the 15-17 yard gaps for the rest of the set. That would put
us at eight clubs, with a big 107-yard range and a pretty constant gap
of about 15 yards. How convenient! We could even renumber them 3-PW,
and not even have to think about a gap club.
So why doesn't it get done? Because it doesn't make marketing happy. It
blows away two major marketing advantages.
- We are back to eight clubs in the iron set, so
golfers don't have to pay for nine clubs.
- If we renumber them to something reasonable, we lose
the advertising advantage of distance --
which of course was due to lofts being jacked up by more than a club.
So far, we have been assuming that loft is loft, and the clubhead is
traveling level as it strikes the ball. That may indeed be the case,
but better players get better impact by leaning the shaft forward. In
order to do this, they affect both the dynamic loft and angle of
attack. Let's look at what this does to impact -- and what it does to
distance and gap.
The pictures show the clubhead striking the ball. The black circular
arc is the path of the clubhead, and the red dashed line is at a right
angle to that circle at the impact point. The red dashed line is
actually a radius of the arc.
- The novice golfer believes that impact should occur
where the clubhead is at the lowest point of the swing. The consequence
is that the angle of attack is zero (that is, the clubhead is
traveling level at impact) and the loft is simply the loft built into
When I say "novice", I don't just mean beginner.
The majority of players I run across believe this, or at least strike
their irons as if they did. (Most do believe it.) Only the best 20-30%
of the golfers I encounter fall in the intermediate or expert category.
intermediate golfer strikes the ball before the clubhead has reached
the bottom of its arc. The result is that the shaft leans forward and
the dynamic loft (in TrackMan terminology) is reduced.
But the shaft still lies on the radius of the arc (red dashed line), so
the spin loft has not changed. The
ball will take off at a lower launch angle than the novice, but with
the same spin.
players and elite amateurs have learned how to lean the shaft forward
even more than the perpendicular to the arc. They get even lower
dynamic loft and also lower spin loft. The result is a still lower
launch angle and less spin for the same clubhead speed. By the way, the
bottom of their arc is also likely to be more forward than the
intermediate golfer as well.
Here is a table of the relationships, where A
is the downward angle of attack, L
is the loft built into the clubhead, and X
is the extra lean forward of the arc's radius.
- A - X
only reason I bring up the ball strike for this discussion is that it
affects the distances and gaps. Let's look at the graphs to see what
happens with a novice (A=0),
an intermediate (A=3°),
and an expert (A=4°,
X=2°). The curves all use a single-length set at 80mph
In the graphs, the novice is blue, the intermediate is green, and the
expert is red.
first thing we notice is that long-iron droop becomes a problem as
shaft lean increases. And it should! Shaft lean decreases the
dynamic loft, and we saw earlier that it is low loft, not the actual
length of the club, that causes the droop. In all fairness, we are
keeping the clubhead speed constant for comparison purposes; a real
expert would have enough additional clubhead speed that the long-iron
droop would be much less of a problem.
But shaft lean also
increases the distance for the middle and shorter irons, and for the
same reason. The reduced loft makes the club behave more like a longer
The combination of long-iron droop and hotter short irons
means that lean reduces the range. In fact, the reduction is quite
marked -- unless you have enough clubhead speed so droop doesn't occur.
For the 80mph speed for these graphs, here are the ranges:
first blush, it would appear that the novice strike is better, because
it gives a larger range. There are a few reasons this conclusion would
- The value of iron shots is not maximum distance, it
difference. Yeah, I know; distance sells. But it doesn't
necessarily score. If you could hit your stock-swing 5-iron either
170-175 yards or 170-190 yards, which would you want. The macho pick is
the latter, but the scoring pick is the former. And forward lean gives
a more consistent ball strike and more consistent distance.
- You weren't paying attention! For most clubs, the
greater shaft lean gives more
not less. It is the range that is smaller, not the distance for most
clubs. The range is shrunk by (a) long-iron droop, and (b)
longer-hitting short and middle irons.
- With more clubhead speed, the
intermediate and expert will suffer less droop, thus less loss of
range. For novices, seniors, women -- golfers who don't have the extra
clubhead speed -- I recommend ditching the longer irons for hybrids or
lofted metalwoods. Avoid the droop altogether. (I have done it myself;
the longest iron in my bag is a 5-iron.)
There are two good reasons for considering a single-length iron set:
A good gap pattern is important for all iron sets. That means something
needs to be done to restore the loss of gap ("droop") for the longer
irons. It is especially
important for single-length sets, because you don't get
any extra clubhead speed from club length. Strategies that can be
effective are larger loft spacing or higher COR in the less-lofted
irons. One thing that does not work is more of what the major companies
have been doing: making stronger middle irons resulting in small loft
spacing on the less-lofted irons.
allows the same swing plane for every club, the same heft and flex
measure (no matter what your favorite measure). It essentially allows
the same swing to be made with every iron in the bag.
- If you can't hit longer irons as well as shorter ones, a
single-length set allows you
to get most of the distance of the longer iron, but with a shorter
club. If this is your motivation, you might also consider single-length
clubs for the longer clubs and conventional-length clubs for the
shorter clubs. I have seen both approaches work, depending on the
friend Ed Reeder feels an Iron Byron (robot) test would be very
interesting, because some of the comforts and discomforts single-length
users have expressed are mostly mental. I disagree. The computer model
is sufficiently "Iron Byron" to point out the reduced range of
single-length. Any benefit that comes from a single-length set must
offset that disadvantage. And any such benefit is due purely to the
difference between a human golfer and Iron Byron -- mental and
coordination. Single-length clubs reduce the golfer's needed repertoire
of swings. Longer irons are harder to hit. So the single-length clubs
are, for many, easier to hit consistently and with confidence. These
are not factors that Iron Byron can test. Nor, for that matter, can my
computer model, which assumed a clean, high-smash-factor hit for every
If you are still interested, what single-length set should you get?
That is considered on the next
of this article. I compare the sets' design features and
specifications. Among other features of the clubs, I compute the gap
patterns using the
same techniques and assumptions that I did on this page.
Last modified -- 12/17/2016