Adding casters, direct to wood, or add some plywood to disperse the stress?

[wildbil52]

I bought some casters for my Midway Cabinet (Mortal Kombat).  Was about to attach them when I wondered if I should add just a half inch of plywood between the caster and teh bottom of the cab to disperse the weight a little bit.

First time adding casters to a cabinet so thought I'd see what people here like to do.  Thanks in advance.

[johnrt]

I don't think that's neccessary. The plywood is a soft material anyway so I don't think adding MORE plywood will do any good.

[yotsuya]

I always bolt the casters directly to the bottom. No issues.