Is inactivity the key.

Now before I start this is purely for arguement sake I'm just trying to get a few opinions. It's only a theory (and not even a good one) and like most theories I'm sure it'll be shot to ribbons in no time. But I got thinking about about Floyd's record and that of the great Rocky Marciano. Both of course undefeated as pro's is that purely down to there skill and ability, or is it because inactivity. As we all know Rocky retired undefeated aged 30 (which even by todays standards is pretty young) and after only 49 fights (which again was barely getting started as far as other boxers of the day). And the still unbeaten Floyd. Either love him or hate him, I think we're all resign to the fact he hasn't been fighting any where near as much as he could. Having only 4 fights in the past 5 years. Is inactivity the key to a legendary record, or should I get back to work. One last thing I dont want anyone thinking this is a stab at either fighter. As far as I'm concerned thier both amazing fighters and great champions.