Game Improvement Irons Aren’t Workable – Golf Myths Unplugged

…Or Are They?

We recently debunked the idea that blades are easy to hit, and today we’re after the other half of the blade-players’ rationale: shaping shots is only possible with blades.  You hear this idea everywhere from the clubhouse bar to the online forums to the PGA Tour broadcasts, so we put it to the test to bring you the facts.

The Myth

Game Improvement Irons Aren’t Workable

How We Tested

For this test, we brought together seven golfers.  Each one hit three irons – a blade, a players cavity back, and a super game improvement iron.  All irons were tested using the same shaft and were set to the same loft, lie, and swing weight.  Each player hit ten shots with each iron.  For this test, we only used the data from “pure” shots as determined by both impact tape and Trackman smash factor readings.

All testing was done at and with the help of Club Champion.

The Results

Before discussing the details of our findings, I want to be clear about what we were testing.  We wanted to find out if blades curved the ball more than GI or SGI irons relative to the face-to-path relationship.  As stated above, we only looked at shots struck in the center of the club face so as to minimize the impact of gear effect on our findings.

With that said, this myth is busted.  For every degree of face-to-path variance, the blade curved the ball 7.2 feet.  For the cavity back iron that number was 7.3 feet, and it was 6 feet for the SGI iron.  In short, no matter what kind of iron you’re swinging, the ball will curve when your club face deviates from your club path.

For those that would quibble about the difference between 7.2 and 6, I want to emphasize what an incredibly small difference we’re talking about.  Most people consider a functional face-to-path difference to be no more than 3 degrees.  With that in mind, you’d be claiming that the SGI iron is “unworkable” because its shot lands 3 feet or less from where the blade’s does.

Other Considerations

While the data clearly shows that you can shape shots with an SGI iron, there are two other things to be considered when thinking about shot shaping.

First, you need to play an iron that allows you to manage the club face and face-to-path relationship.  Most of our testers use players irons, and that showed in the data.  We saw larger face-to-path variances with the SGI iron and poorer club face control in general.  This speaks to the importance of personal preference in club fitting.  Some players will manage a blade very well.  Others will create much better face-to-path relationships with a larger iron.  It’s important to find what works for you, and equally important to remember that just because something doesn’t work for you doesn’t mean it won’t work for others.

The other is controlling trajectory.  It is entirely reasonable to think that it is be harder to hit low shots with a club that has a very low CoG as most SGI irons do.  If flighting shots is an important part of your game, you may want to avoid wide-soled clubs with low centers of gravity.


It is our hope that our findings give you the freedom to choose the irons that will help you play your best.  You do not need to sacrifice forgiveness to shape shots – you just need to manage the face-to-path relationship.  The next time you’re changing our your irons, work with a qualified club fitter and trust the data, not the myths.

The following two tabs change content below.

Matt Saternus

Co-Founder, Editor In Chief at
Matt is a golf instructor, club fitter, and writer living in the northwest suburbs of Chicago. Matt's work has been published in Mulligan Magazine, Chicagoland Golf, South Florida Golf, and other golf media outlets. He's also been a featured speaker in the Online Golf Summit and is a member of Ultimate Golf Advantage's Faculty of Experts.

Latest posts by Matt Saternus (see all)


  1. I think this is a little bit beside the point. Hit any club with a shut or open face and it will curve. I think what makes the difference between a blade and an SGI iron with regard to working the ball is the turf interaction from the shape of the sole of the iron. SGI irons have big wide soles with more bounce to help correct fat shots. Blades have thin soles. If you’re hitting a shot with a shut or open face the heel or toe of the sole will hit the turf first. An SGI iron will want to “bounce” back to square as it hits the turf. That makes it tougher to get to impact with the face open or shut. Yes, if you get to impact with a shut face, the ball will curve. What makes an SGI iron tougher to curve happens before you get to that point, so you’re not testing for it. Myth not busted.

    • Matt Saternus


      If you can’t manage sole/turf interaction while opening or closing the face 1-3 degrees, that’s your swing, not the club. There is an element of personal preference and how a club works for your swing, but I addressed that in the article and it has nothing to do with the ability of the club to curve the ball.

      Also the idea that the club will somehow “bounce back to square” is nonsense. If you dig the toe, the face will end up more open at impact. If you dig the heel, it will end up more closed.


  2. You said you only looked at “pure” shots and shots struck in the center of the club face.

    What are you really trying to test with that? By analyzing only pure shots that hit the center of the club face you have taken everything “game improvement” out of the equation. Are you trying to show that perimeter weighting of irons doesn’t matter on shots that are “pure” and hit on the sweet spot? Of course it doesn’t. It only matters on shots that aren’t hit on the sweet spot. Similarly, it makes no difference how wide an iron’s sole is or how much bounce it has on a perfectly struck shot. It’s when a player hits a fat shot or misses the sweet spot that those features of an SGI iron come into play and “help” a bad golfer.

    If I boil down your analysis, it says to me that shots struck perfectly on the sweet spot will obey the laws of physics and curve based on face angle and path and the elements of club design that make an iron a “game improvement iron” (e.g. perimeter weighting and fat soles) don’t matter because the shots have been struck perfectly.

    Phrased differently, if you’re a skilled player and can hit the ball purely and on the center of the club face, you can make an iron shot curve regardless of whether you’re playing a blade or an SGI. I totally agree with that. I’m a skilled enough player to be able to do that and I empirically know it’s true. But so what?

    I also empirically know that if I don’t strike the ball purely that the same miss will be very different if I’m swinging a blade or if I’m swinging an SGI iron. And I believe that difference is magnified if I’m trying to curve the ball. If I’m hitting a low draw with a blade 4-iron and I mishit it, compared to the same magnitude of mishit on the same shot with an SGI iron, I think the SGI iron will go straighter (and probably carry farther, so it’s a double edged sword).

    That’s not what you’re testing. But I think that is what you should be trying to test.

    I hope you will. Somehow. It’s obviously a tough test to design. I think the challenge may lie in figuring out which shots to include and which shots to exclude. For example, if I try to hit a draw and I manage to draw 8 balls out of 10 with a blade but only 2 balls out of 10 with an SGI iron, if I exclude all the shots that didn’t draw I will get the same data and erroneously conclude that SGI’s work the ball as well as a blade. But if I look at it by asking what percentage of all shots drew, I would come to a very different conclusion.

    I wish you luck in your testing and look forward to reading the next chapter.

    • Matt Saternus


      We were testing whether or not SGI irons curve the ball as much as blades given a centered shot and equivalent face-to-path (FtP) relationships. We stated that very clearly, tested that, and presented the results. We’re not interested in things that people “know intuitively.” Things people “know intuitively” are the things that we want to test and put data to so that they can be substantiated as facts or thrown out.

      The purpose of removing off-center hits, as I explained above, was to eliminate gear effect. No good player works the ball with irons by mishitting it.

      The test you that you’re suggesting, as I understand it, would do nothing except show how adept our testers are at managing various types of irons. All the data gathered in this test and our previous test on the forgiveness of SGI irons shows that some players can manage a small (or big) iron well, others can’t. A player may swing a blade with a functional club path and then swing the SGI iron into left field, or vice versa, regardless of what they’re trying to do.

      If you’re suggesting some kind of test where we dictate a FtP relationship and then test various degrees of mishits, that would only be possible with a robot. No human can simultaneously maintain the exact same club path, club face, FtP while manipulating strike location and changing clubs. At this time, robot testing is not something we’re interested in. Human testing is much more interesting and relevant in our opinion.



  3. I think that curving the ball is the simple definition of “working the ball” and is accepted by the masses, but I don’t think it’s a correct definition. Your note regarding center of gravity is more relevant in the big picture of “workable”. Like you said, curving the ball left and right is simply a matter of face to path, but trajectory is where “workable” really makes a difference.
    I regularly hit low cuts and draws and I wouldn’t dare rely on a SGI club for this. SGI clubs are designed to fight the golfer’s natural swing flaws and help get the ball in the air.
    With all due respect (and I know this may sound arrogant) most people that make “workable” a talking point can’t even “work” the ball, and they are just referring to curving left or right. It is near impossible to hit a straight shot. 99.999999% of shots are curving one way or the other, but that doesn’t mean that everyone that slices or hooks a ball is “working” the ball. Working a ball is more a result of the players skill than the club characteristics. It takes a lot of skill, understanding of the cause and effect and practice/coaching to really be able to consistently work the ball for all shots.

    So I would say that this conclusion is a bit flawed and the result should be more focused on trajectory than curvature. And in that case it seems that blade and player irons are indeed more workable than SGI clubs. But that doesn’t mean that SGI aren’t workable, just that they are more difficult because of the intent of their design.

    • Matt Saternus


      You may want this test to be something that it isn’t, but that doesn’t mean the conclusion is flawed. We were explicit about what we were testing, how we tested, and the results that it produced. If there’s some other test you’d like to see, feel free to make a suggestion.


Leave a Comment

Your email address will not be published. Required fields are marked *