The most effective pitch in baseball is still the fastball. If you can spot it and throw with the velocity that Lidge throws it, nobody can touch you, even if they know its coming. If you can't spot it, and you don't know where its going, you are going to leave it over the plate and you are dead in the majors. The biggest single problem is the lack of spotting the fastball. If he could control where it was going, he could only throw fastballs and still be effective. Its obvious he still has "stuff." He strikes out a ton of people and throws in the high 90s. But once you lose control, if you can't get it back, you are toast.
And the weird thing is that that was on a hanging slider, yet it has now been his fastball that is getting hammered.