- AMB Centaur Pearl

First Impressions
The Visionary AMB Centaur Pearl, which hit the market in December 2004 and is known to many bowlers as the Bronze Centaur, is a bowling ball that stands out for its innovative core technology. The cover of this model is a reactive pearl material called AMB Centaur Pearl, finished out of the box with a 1500 polish. This extremely smooth surface is deliberately designed to let the ball glide through the heads very easily and without resistance. Inside works the ball's true centerpiece: the asymmetric Centaur AMB core. This is a modified, noticeably stronger version of the original Centaur design, with a lengthened lower arm and a heavier top cap. The essential innovation, however, is hidden in the abbreviation AMB, which stands for Anti-Mass Bias. Instead of using a dense, heavy material to create the desired imbalance as in conventional balls, the manufacturer integrated an extremely light cap on the exact opposite side of the core. This negative mass bias consequently creates extremely strong dynamics on the target side. At a ball weight of 15 pounds, this special core shows an RG of 2.560 and an immensely high differential of 0.065. These enormous specifications point to a massive flare potential of over five inches, which should keep bringing a great deal of fresh surface to the lane as the ball rotates.
Comparison
Comparing the Visionary AMB Centaur Pearl with a proven and well-known benchmark like the Storm Phaze II, the conceptual and reactive differences become very clear. The Storm Phaze II uses a symmetric core design combined with a matte solid cover. This construction aims at early, strong traction in oil and a very controllable, evenly rounded arc over the full length of the lane. The Visionary AMB Centaur Pearl behaves fundamentally differently here. Thanks to its highly polished pearl cover, it crosses the first boards far more effortlessly and stores its rotational energy for the last third of the lane. But as soon as it leaves the oiled areas and meets friction, the highly dynamic asymmetric core intervenes massively. Unlike many classic pearl balls, which often show a pure and sometimes hard-to-control skid/snap motion, the AMB core forces the ball into a stable roll phase somewhat earlier because of its extremely high differential. This means the hook at the breakpoint is noticeably more angular and aggressive than with the Storm Phaze II, yet at the same time stays more controlled and more resistant to carrydown than with conventional pearl models, which often react to carrydown with a breakpoint that is too late and too weak.
On the Lanes
In practice, the Visionary AMB Centaur Pearl finds its absolutely ideal application on medium to dried-up lane conditions or on typical house shots. Especially when the transition sets in over the course of a tournament, the front boards noticeably lose oil and the oil distribution becomes more irregular, this model's strengths come to light. The polished surface helps you keep reaching the pocket absolutely clean and without early energy loss. Immediately afterward at the breakpoint, the extremely strong asymmetric core should ensure that the ball does not slide out uncontrollably but instead develops a powerful, definable hook toward the pins. This combination should clearly maximize carry on a solid pocket hit. A significant technological advantage of this particular design shows up during drilling at the pro shop: with conventional strong mass bias balls, drilling the thumb hole often removes a large portion of the heavy core material, which greatly reduces the original dynamics. Since the mass bias on the AMB Centaur Pearl is created by the extremely light cap on the opposite side, you drill into less dense areas on this ball. As a result, the core's enormous dynamics remain almost fully intact with nearly any drilling layout. If you are a player type with very low ball speed and an extremely high rev rate, however, some caution is advised, since the extremely high differential combined with the driest conditions can cause the ball to use up its energy too early despite the pearl cover.