- Katana Yasha

First Impressions
The Radical Katana Yasha is something special in the January 2020 lineup, since it's a so-called performance polyester ball that was developed primarily for the Asian market and only found its way into Western bags by roundabout routes. Visually, the ball stands out with a striking design themed around Japanese mythology. The key technical feature is the combination of a hard, smooth polyester surface that generates almost no friction with the original Katana Asymmetric core. Unlike conventional spare balls, which often have nothing more than a simple pancake core, the Yasha shows serious numbers: a 2.503 RG and a 0.050 differential. That means the ball skids straight like a plastic ball but carries the dynamic imbalance of a high-end reactive ball on the inside. The surface is highly polished out of the box to guarantee maximum length.
Comparison
In the polyester category, the Katana Yasha clearly sets itself apart from standard models like the Storm Ice or the Brunswick T-Zone. Where those balls often wobble and offer little track stability, the strong asymmetric core in the Yasha produces very stable motion (track flare), even when the ball isn't supposed to hook. The concept is comparable to the legendary Hammer Black Widow Spare, which also paired a high-performance core (Gas Mask) with a plastic shell. Compared to a urethane ball like the Purple Hammer, the Yasha is even cleaner through the heads and doesn't react at all to dry oil unless the lane is extremely short or burned up. So it's a specialist, not an all-rounder.
On the Lanes
The primary purpose of the Radical Katana Yasha is picking off single pins, especially if you generate a lot of hand rotation. Thanks to the asymmetric core, the ball stays truer to its line than a conventional plastic ball even on a less-than-clean release. Second, it's a secret weapon on extremely dry or short sport patterns, where even weak urethane grabs too early. Here the core allows the Yasha a certain amount of "controlled hook" at the very end of the lane without giving up energy beforehand. It's a luxury spare ball for tournament players who don't want to compromise on core dynamics, even when they're throwing it straight.