Blades vs. Cavity Backs, the Debate Continues

Good debate and posts going over on Brian Manzella's forum about using Cavity Backs vs. Blades and I wanted to share my thoughts.


I'm a believer in the blade style iron. I don't think it's a coincidence that the great ballstrikers all used blades and the best rounds in the history of the game were almost all done with blade style iron.

I'll name off the top of my head, the ten best all time ballstrikers I can think of:

- Ben Hogan
- Moe Norman
- Sam Snead
- George Knudson
- Johnny Miller
- Lee Trevino
- Nick Price
- Tom Watson
- Mac O'Grady
- Jack Nicklaus

I'm pretty sure all of them used blades. Knudson is questionable since I don't know of his endorsement deals.


With the cavity, it's a more forgiving when it comes to the effects that the clubface, clubhead path and low point have on the ball. Now we are seeing more of a 'player's cavity back' iron involved with the game.


Manzella's contention is that he can hit some cavity backs better than any blade iron available and test it out on Trackman's 'combine' application.



My contention is that after reading Michael Lavery's book 'Whole Brain Power' (see Lavery in the pic above), I believe that people who do not test their motor skills usually see them erode.

So, when you have a set of irons like cavity backs which allow golfers to be less precise with their clubface, clubhead path and low point control...they'll eventually become less precise with those facets of impact.

Here's what Manzella mentioned:

That science is called the Moment of Inertia—the measure of an object's resistance to changes to its rotation.

The higher the MOI, the harder it is for the club to be "twisted" by an outside force.

The lower the MOI, the easier on purpose, during the swing, twisting is.

Blade irons, with all of their mass distributed more or less evenly throughout the head, have a far lower MOI than say a hollow-headed 460cc Titanium Driver.

And much less than a cavity back iron.

So, for the highly skilled golfer, the ability to "twist", or manipulate the clubface during the swing, is "scientifically" easier to do with a blade iron.

But what about a higher MOI twisting less on off-center hits?

Well, if the ball is contacted on the sweetspot of a blade iron, not a big problem for the Hogan's, Nelson's, Snead's, Nicklaus', Miller's, and Eldrick's of the world, that resistance to twisting during an off-center impact, is not a big benefit to them.

So, why would anyone play with a cavity backed club?

Why would anyone play with a hybrid?

Because, mere mortals don't hit the sweetspot like a David Toms, and can't control the clubface like a Lee Buck Trevino.

What some point to is that the majority of golfers on the PGA Tour use cavity backs. In fact, I did a look a few months ago at the top 50 ranked players in the world and 17 of them played blades at the time, 30 played CB's and 3 played a very mixed set.

And when I think of great ballstrikers on the PGA Tour, I think of Kenny Perry, Heath Slocum, Hunter Mahan and Joe Durant...all of which use cavity back irons.

So what gives?

Well, the courses (like I've mentioned in the past) have become more 'carry oriented' and you have to hit the ball higher and longer than in the past. Ryan Moore uses Scratch Golf's SB-1 blades, but for the Master he switched over to their cavity back irons because he felt he needed to hit the ball higher for Augusta's greens. Anthony Kim recently said he liked the Nike VR blades over the old Nike blades because he could get them up higher and they would land softer on the greens.

Plus, the course are certainly longer and that's a big thing, particularly on par-3's where one could feel more comfortable hitting a 5-iron into a green instead of a 2-iron.

But, there's also endorsement deals which are far stricter than they were only 15 years ago. Now less and less OEM's are willing to design a set of irons after another OEM's line of clubs and stamp it with their logo and call it a 'prototype.' 15 years ago that happened more often than not. Now, it's pretty rare to see.

Getting back to Trackman. I do believe that many golfers could do the Trackman 'combine' and find themselves performing better with the cavity backs. The problem, IMO, is that OVER TIME with the CB's the golfer can be less precise with their swing because they are not being challenged to be precise with their clubface, clubhead path and low point control.

So *over time* with CB's they could take the Trackman 'combine' test again and find that they still perform better with CB's than blades, but their Trackman combine performance slipped from before. Had they stuck with blade style irons, I think their Trackman performance over time wouldn't slip or wouldn't slip as much (or even get better).

Of course, you need pretty good coaching and dedication to put the time in to building your swing. Like Moe Norman once said, you simply cannot buy a golf swing, one must work for that.

It runs along the same problems I have with irons becoming longer, lighter, lower lofted with more upright lie angles. Over time most golfers develop swings around that. And then when they start hitting shots off the toe, the clubmaker tells them they need more upright clubs.

It's really up to golfer in the end, but I think they need to be fully aware of the risks and rewards of both styles of irons.







3JACK