William L. Coney Blog: First Look

The story of Mizuno’s recently released MP-18 iron family is about returning to traditions. The S18 line doesn’t have nearly the history of the MP, so tradition isn’t much of a concern at this stage of the game. We’re talking about a second-generation product, so there’s not much to go back to; instead, Mizuno is moving forward with the type of year over year – in Mizuno’s case, two-year over two-year iterations we’ve come to expect.

An S Refresher

Mizuno released the original S (Silhouette) wedge in 2015. While that’s not exactly the distant past, it predates Mizuno’s redefining of the JPX category from game-improvement to technology-driven. At the time, Mizuno had a JPX wedge in the lineup as well as its T and R series wedges, both of which carried the MP prefix.

Simply put, Mizuno had traditional wedges in its lineup. It had Game improvement wedges too. The goal for the S line was more or less to split the difference and incorporate the best of both worlds into the design. S was a refined, though slightly oversized wedge with a bit of extra forgiveness built-in. The Silhouette wedge marked the beginning of a new category or sorts.

Also of note, as part of Mizuno’s push to own the color, the S5 came in blue.

I suppose the S18 makes for a bit of a curious release what’s shaping up to be a defining year for the MP line. S is not MP – by design, it’s a tweener. Though more compact than the recent run of game-improvement irons we’ve seen, the S18 shares the aggressive aesthetics of the JPX series. The lines are a mix of crisp and soft, the footprint is noticeably larger than the T7, and that’s especially true along the topline.

Beyond aesthetic differences, what you get with the S18 is the next iteration in Mizuno wedge technology.

Mizuno’s generations-old T10 brought us loft-specific grooves. The T5 (Mizuno has never been high on numerical order), gave us loft-specific sole grinds. The S6 brought us a new shape – arguably an entirely new wedge category along with a beautiful blue finish. Last season’s T7 introduced loft specific head shapes and 1025 Boron in a wedge. The S18 offers all that and more.

What’s New with the S18

As you would expect, with the introduction of the S18 wedge comes several noteworthy changes from the original

Loft Specific CG Placement

This most significant advancement in the S18 lineup is the addition of loft-specific CG placement. Most notably, Vokey is already strategically positioning CG based on the desired performance characteristics of each loft. It’s smart design, so it makes sense others would follow suit.

As the loft of wedge increases, the center of gravity location moves higher. The goal is to align the sweet spot with the typical impact position and ultimately produce a more penetrating ball flight with more spin to hold greens.

As part of the CG story, the back pad is wider and deeper, and hosel lengths vary.

More Aggressive Sole Grinds

The description perhaps sounds more imposing than it actually is. Mizuno isn’t doing anything radical here; instead, changes to the sole grinds are meant to create more separation between the various loft and bounce combinations. Ultimately that means greater variance in the amount of sole relief between the low, mid, and high bounce options.

While wedge fitting is far from an exact science, the general rule of thumb is that players with a steep angle of attack and golfers who play in soft conditions are likely to benefit from higher bounce options, while shallower angle of attack golfers (sweepers) and golfers who play in dry conditions are more likely to benefit from low bounce options.

If you happen to be like me – a golfer with a steep angle of attack who plays in dry conditions – Mizuno’s recommendation is to defer to the angle of attack, but keep in mind that bounce is your friend. It probably wouldn’t hurt to get fitted either.

Gunmetal ION Finish

Gone, at least for now, is Blue ION-plated finish that debuted with the S5. Replacing it in the line is a new Gunmetal Black ION-plated finish. While the finish should prove to be distinctive in the marketplace, the wear characteristics are similar to the blue. Lefties may again find themselves disappointed as Mizuno is making left-handed wedges in Satin finish only.

Other Noteworthy Features

1025 Boron, which made its wedge debut with last season’s T7 is now part of the S-Series story. The benefit of Boron in a wedge is its durability. Longer lasting grooves mean you don’t have to replace your wedges as often. Mizuno is listing the number at 30% less wear than 1025E wedges. Bear in mind, that’s not some sort of artificial spin-life measurement; it comes from comparative groove scans of sandblasted wedges 1025E and 1025 Boron wedges while using Luke Donald’s S6 for reference.

As with other Mizuno wedges, the S18 leverages Mizuno’s loft-optimized Quad Cut Grooves. Part of Mizuno’s offerings since the T10, Quad Cut grooves feature narrower and deeper grooves on stronger lofted clubs (the ones you’re more likely to hit with full swings), and Wider/Shallower grooves on weaker lofts, which provide more spin on partial shots.