Mizuno MP-25: Technology vs. Specology juice

Written By: Tony Covey

That’s right, Mizuno claims that the MP-25 signals a new era for better player’s irons. That’s a bold statement from a company that generally doesn’t say much of anything at all.

Just what is Mizuno talking about? What’s behind this new-found brevity?

The answer, it turns out, is Boron.

A Brief Re-Introduction to Boron

Mizuno first signaled its use of Boron in irons last season by sending a block of Boron to my house. Most of you will also recall that my chunk of Boron was Mizuno’s clever way of teasing the release of its JPX-850 forged irons. Those were Mizuno’s first Boron-infused product and are noteworthy because, although they play like true game-improvement irons, they look the part of a better player’s forging.

When Boron is added to mild carbon steel it encourages the formation of Martensite as opposed to Ferrite (Confused? Let me google that for you.), the resulting material is 30% stronger, but not harder than conventional 1025 mild carbon steel. That last bit touches the very soul of the company. Its line is that nothing feels like a Mizuno (there’s even a hashtag, which is probably more value than a trademark these days), so it’s important to understand that the addition of boron doesn’t compromise what we might call that traditional Mizuno feel.

Figuring out how to achieve the desired results using Boron in an iron took 6 years of development, and Mizuno has several patents pending for the process. For now, they’re the only company of note using Boron, and while that’s all well and good, as a consumer of golf equipment what should matter to you isn’t the material itself, but rather what it allows Mizuno to do.

Through the addition of Boron to the forging process, Mizuno is able to create irons with thinner, more responsive faces, while freeing up some mass which, as it almost always is, can be reallocated to the perimeter of the iron for more forgiveness.

Needless to say, Team Mizuno is excited about Boron.

Redefining the MP iron

When most of us think about Mizuno’s MP line, we think clean, relatively compact, dare I say traditional offerings. What we don’t generally think about is distance. And for Mizuno, that’s a bit of an issue.

What we haven’t mentioned yet is that the MP-25 is the direct replacement for the MP-54. By most accounts the pocket cavity MP-54 is a very good iron. It sits on the the outer edge of the MP lineup (just before things start to get all JPX-y). It’s bigger than the other irons in the MP lineup, which doesn’t always sit well with lower handicap golfers, and while it’s generally regarded as a reasonably forgiving players iron, it has a reputation, fair or otherwise, for lagging behind when it comes to distance.

Simply put, some think the MP-54 is too big. Others think it’s too short.

Those are two problems that are inherently at odds with one another. To get more distance, manufacturers typically resort to larger head sizes, offset, and what the Mizuno team refers to as Specology. While the word might be new to some of us, we’re all familiar with what it means; longer shafts and stronger lofts.

Mizuno’s goal was to improve upon the MP-54 with Technology, not that Specology stuff we just talked about. That means is finding a way to create a more compact iron that actually generates more distance than what came before, and those performance gains had to be realized without cheating loft or increasing shaft length.

How’d they do it?

Yup, Boron.

The primary implication of using Boron for the first time in a better player’s iron, is that it effectively allows Mizuno to challenge the very definition of what an MP-iron actually is.

Using 1025 Boron and a Microslot (yes, the MP-25 has slots hidden in the 3-6 irons), Mizuno was able to decrease face thickness, increase ball speed, reduce spin, increase max height, and increase carry distance by an impressive 7 yards (compared to the MP-54), and Mizuno did it all of it without decreasing loft or increasing shaft length.

Mizuno did it with technology, not specology.

Perhaps of greater significance to better players, Mizuno made those performance improvements while at the same time dramatically reducing head size. For every meaningful physical specification – topline thickness, blade length, and sole width – the MP-25 closely mirrors the MP-15, which fans of the brand know is an irons that’s very compact at address.

vs. Everybody Else

When we talk about sweet spot (or sweet area) size and physical footprints, I find it’s usually helpful to put things in comparative terms. So where does the MP-25 fit among its competitors? Mizuno views the competitive set as primarily the PING S55, Callaway Apex Pro, Titleist 714 AP2, Titleist 714 CB. Among that group, Mizuno claims the MP-25 has the largest sweet area AND the smallest blade length.

That’s impressive, but when you stretch out the set to include a couple of TaylorMade offerings, the MP-25 offers a sweet area nearly the same size as the Tour Preferred MC. While the sweet area of the RSi2 is a bit larger, the blade length is also substantially longer. RSi2 will get you forgiveness, but comparatively, it’s not particularly compact.

This new era that Mizuno talks about is defined by forged irons that offer forgiveness in a more compact footprint. That’s exactly what many of us are looking for.

Pricing and Availability

The Mizuno MP-25 is available for both right and left-handed golfers. Retail price for a set of 8 MP-25 irons is $999 for Project X steel and $1099 for Orochi graphite. As with all irons in the Mizuno lineup, there are no additional up-charges for any shaft in the Mizuno lineup. Retail availability begins September 8, 2015.