[benkahuna]

I think I'm missing something here, perhaps context, because the explanations on why to call a player on the end relative to tightness or aggressiveness don't make sense.

I see no reason why an aggressive player would be bluffing less on the river so that I should call them less. This situations sounds like the only thing I can beat is a bluff.

Is Sklansky just saying that apparently tight players have a greater tendency to bluff on the river?

Is he perhaps talking about tight aggressive players that play fewer hands, but play them more aggressively so a river bluff is more likely?