Rochdale boss Keith Hill was left frustrated with his side's displays in both boxes as they lost 1-0 at Home Park.
Having gone a goal down to Reuben Reid's penalty Dale pressed tirelessly for a leveller in the second half but rarely tested home keeper Luke McCormick.
"We conceded a very soft penalty caused by a catalogue of errors," Hill said. "We had three chances to clear it before it came the ball into the penalty area.
"We have been working on our strategies all week and when you go 1-0 down to what will be a very good home side like Plymouth, it's very difficult.
"I thought the first was relatively even. We had opportunities and so did they. It was too open for my liking.
"We had to dominate the ball in the first half like we did in the second and that was our strategy.
"We kept giving away the simple pass, the clinical must-complete pass and that caused our defenders all sorts of problems because Plymouth counter-attack well at home.
"I was relatively pleased with the second half but there is no solace in losing that game.
"We squandered opportunity after opportunity. To a certain degree the performance was more than acceptable and it was one-way traffic in our favour.
"We should have equalised because we should have made the most of one of the opportunities we had because we put the opposition under severe pressure. With the combination of some good defending and bad misses we failed to score."