How does one determine a great pope from a "terrible" pope?

  Maybe we should hold their behavior up to the two great commandments, or the beatitudes, or to their imitation of Christ, or their willingness to be led by the Holy Spirit or  by the requirements of being a good shepherd, (Ez. 34),  or by walking the talk, or  by their humility, or by their compassion, or by the way they speak truth to power, or by their concern for the poor, or their empathy for the refugee or their compassion for the sinner.

The "terrible popes of the history of the church would not have passed these tests.  Pope Francis on the other hand passes all of those tests and he isn't done yet.