Your dad is the scariest person in the world to you. Most father's enstill this fear in you since birth so its hard to get over that.
I know this felling personally. My dad and I had a run in and he rushed me. Normally I would have reacted faster, but I froze up and he got me.
You always hold back against your dad.
If anyone honestly thinks they can beat their dad, their dad is either old/weak as fuck, wasnt strict enough(meaning not a good dad), or they are liars.