Compare bowling balls
Core numbers are compared in one weight. Some brands only publish them for one weight.
Hammer Black Widow Mania
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Roto Grip Transform Pearl
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Roto Grip RST Hyperdrive Pearl
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Brunswick Strategy
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|---|---|---|---|---|
| Brand | Hammer | Roto Grip | Roto Grip | Brunswick |
| Line | Upper Mid | HP5 | HP4 | Pro |
| Coverstock | HK22 - Cohesion Pearl | Microtrax Pearl | U-R1 Pearl | HK22C² - EVO Pearl |
| Cover type | Pearl reactive | Pearl reactive | Pearl reactive | Pearl reactive |
| Core | Gas Mask | Morph Wing | RST AI | Dual Centric |
| Core type | Asymmetric | Asymmetric | Asymmetric | Asymmetric |
| RG | 2.500 | 2.500 (16 lb) | 2.510 (16 lb) | 2.509 |
| Diff | 0.058 | 0.050 (16 lb) | 0.051 (16 lb) | 0.047 |
| Int. diff | 0.016 | 0.015 | 0.016 | 0.016 |
| Factory finish | 500, 1000, 1500 Siaair / Factory Compound | Power Edge | Power Edge | 500, 1000, 1500 Siaair / Crown Factory Compound |
| Lane condition | Medium oil – Heavy oil | — | — | — |
| Flare potential | — | High | High | — |
| Reaction | Length with aggressive backend | — | — | — |
| Color | Cobalt / Black | Red / Cherry / Shadow | Space Blue / Deep Purple | Black / Blue / Silver |
| Release date | January 16, 2025 | July 10, 2026 | September 19, 2025 | April 16, 2026 |
| Status | Current | Current | Current | Current |
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