Four examples of group identifications with the optical and extended X-ray centers shown. Despite all of these examples exhibiting very confident match criteria, no strong correlation exists between the MHD value (i.e., chance of a match) and the distance between the optical and X-ray centers. In some cases, such as in Figures 5a and 5b, the optical centers even lie outside of the X-ray contour, over 1000 kpc from the X-ray centers.