Say we're on the river facing a pot-sized bet.

According to pot odds, we're getting 2:1 and should call if we expect to win >33% against Villain's range.

Minimum Defense Freq (MDF) tells a different story. It says that since our opponent is risking 1pbs to win 1psb, we need to call 50% of the time or he's auto-profiting with his bluffs. 

Confusing, right?

If we base our decision on pot-odds, we're only calling 33% -- not enough to keep villain indifferent to bluffing with ATC.  If we use MDF instead, now we're calling 50% when (against a balanced range) we're only good 33%. 

So my question is: are pot-odds and MDF supposed to be used in tandem? That is, if you think a villain is trying to exploit you with his bluffs, are you just supposed say "MDF it I call" 50% of the time, and do so with a range that wins >33% of the times you call? 

Somebody please enlighten me.