The Hammer Web M.B. (Mass Bias) continues the performance success reputation of the Web series of bowling balls from Hammer. The Web M.B. features an elongated rendition of the Spheroid Core design. This core shape gives asymmetry as well as increased ball reaction that is desired by Web and Hammer fans. This upper-mid performance ball has a coverstock base that was previously found on Black Widow bowling balls, the Semtex NE Pearl was updated and ideal on medium lane conditions.