I took apart a '40's penn model 49 reel to clean and lube it. I found a very similar design to the bait casters of today. Here we are many decades later the same similiar design is still used.

For starters the the design is perfect, it´s only been improved through time.

Hmm...

 

Knuckle buster, no level wind, 2 bearings, 3.5:1 gear ratio and weighs nearly 2 lbs (30 ounces).

I suppose at the base the commonality is it retrieves line.

It is almost perfect.. I think all reels should have a dual bearing supported pinion gear, or at least the power fishing sized reels; the finesse reels don't need the extra bearing IMO.