An ABEC 11 bearing is the fastest bearing because it has a higher Annular Bearing Engineers' Committee rating, which means it is more precise and faster than lower-rated bearings. The ABEC scale is the method used by Americans to rate the accuracy and tolerance of bearings, as of 2015.
Most ABEC scales only go up to nine, and anything over this level is exceedingly fast. The numbers refer to a degree of roundness in the inner and outer races of a bearing. As the ABEC rating increases so does price: ABEC 1 bearings are the cheapest, most crude bearings, while ABEC 9 bearings are extremely costly and smooth. Companies that sell cheap ABEC 9 bearings are most likely selling bearings that are not rated truthfully according to the ABEC scale.