(just click on the graph to get an image you can actually read...)
These are the top four Oriole pitching careers in terms of WAR. The seasons are arranged from greatest to least, not in chronological order.
As you can see, (and it's no surprise) Jim Palmer stands alone. Mussina is in the next tier although if he had remained an Oriole he probably would have bene the career WAR leader for Baltimore even though he never reached the heights that Palmer did.
Next is Dave McNally who suffered from a sharp decline. People remember Milt Pappas, almost like a punchline, as the player the Orioles sent to the Reds to acquire Frank Robinson. Pappas was a hell of a pitcher.