Fifteen years ago almost every iron set on this bench was eight identical castings in descending lofts. Today more than half of what I build is blended: a hollow-body four and five, a cavity six and seven, a compact eight through pitching wedge. That is a genuinely better idea than the old single-model set, and it introduces a problem that the old sets did not have.
The problem lives at the crossover, and it is measured in fractions of a millimetre of face progression.
What a Smooth Set Looks Like on the Gauge
Within any single model, progression reduces steadily as loft increases. Long irons carry more, short irons carry less, and the reduction per club is small and consistent. Plot it and you get a line with a gentle, even slope. That evenness is what makes a set feel like a set: each club looks like a slightly smaller version of the one above it, so your address position barely changes.
Now stitch two models together. Each has its own even slope, but the two slopes do not necessarily meet. The hollow long iron may sit noticeably more progressive than the cavity mid iron it hands over to, or noticeably less. At the crossover club, the line jumps.
What the Jump Does to the Golfer
The golfer will not describe it as a progression problem, because nobody does. What they say is that the six iron feels like a different club, or that the five is easy and the six is a fight, or that there is a gap in the set they cannot explain because the lofts are correct. I have heard all three versions in this bay in the last year.
Nobody arrives complaining about face progression. They arrive complaining about one club in the middle of the set that never feels right.
The mechanism is the same as in a single club: address position shifts, hands settle somewhere slightly different, delivered loft moves, and the carry step between those two clubs stops matching the others. On a gapping chart it looks like a loft problem, and bending the lofts to fix it makes the set worse, because the real cause was geometric rather than angular.
Where the Crossover Should Go
Manufacturers publish recommended crossovers and they are usually reasonable, but they are chosen for an average golfer rather than for you. On the bench I choose the crossover from three inputs:
- Where the measured progression step is smallest. Sometimes moving the crossover one club in either direction cuts the step in half. That is free improvement.
- Where the golfer's delivery changes. Most players deliver the long irons noticeably differently from the scoring irons, and the crossover ideally sits at that same club.
- Where the carry gaps are already awkward. If there is a natural pinch point in the set, that is a good place to change models rather than a bad one.
Those three rarely all point at the same club, and the compromise is a judgement call. But it is a judgement made with three measured inputs rather than a catalogue recommendation, which is the whole difference.
Sole Width Steps at the Same Seam
Progression is not the only thing that jumps at a crossover. Sole width and bounce usually step too, and in the same direction: hollow and cavity long irons tend to have wider soles and more effective bounce than the compact heads below them. That is intentional, and mostly helpful, but it means turf interaction changes at the seam as well as address geometry.
If both step at the same club and both step in an unhelpful direction, the crossover club becomes the worst club in the bag. I have rebuilt several sets where the only change was moving the seam one club and re-gauging everything, and the golfer reported the set felt entirely different.
What to Ask Before You Buy a Blended Set
If you are buying a blended set anywhere — here or elsewhere — the useful questions are these. Has anybody measured the progression step at the crossover? Does the sole width step in the same direction? Was the shaft trimmed to each model's own chart or to one chart across the whole set? Three questions, and the answers tell you a great deal about how the set was assembled.
A blended set built carefully is better than any single-model set for most golfers. A blended set thrown together from two catalogues because both looked good is frequently worse than either model on its own.
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