From July 18 through the 24th, the Orioles' rag-tag group of starting pitchers threw seven consecutive quality starts. They pitched to a collective 2.47 ERA over that stretch, but oddly if you ignore the runs allowed the stretch didn't look nearly so cohesive or dominant. As a whole, the starters struck out fewer batters than the major league average, even got fewer swinging strikes than the major league average, and gave up more home runs than the major league average. The one saving grace during the roll was that the starters were frugal with their walks.
Those things happen when you're talking about seven games, and even if it rings untrue to say that Tommy Hunter's 7.1 inning, 1 strikeout, and 1 home run performance (July 18) was "quality", you can wave it off easily because, hey, that's baseball, man.
Now for the second time in less than a month, we're looking at another nice little roll. And again, over the past three starts the runs allowed pop out at you. Wei-Yin Chen, Miguel Gonzalez, and Chris Tillman have a combined 0.42 ERA, and they've needed all of it, because the Orioles' bats are the Orioles' bats. Unlike the earlier streak, these starts have all been unarguably "quality". The big positive is that they've all featured exactly no home runs allowed.
Good things happen when you keep the ball in the ballpark. That's a tall order, of course, but - like Earl Weaver said - the easiest way to score runs is to do it on one swing, and when you don't do that, it gets tougher. Consider Miguel Gonzalez's start: as many walks as strikeouts, and at a below average rate for both. He was on fire in his previous start, inducing a lot of swings and misses, but he didn't have the same nasty change-up this time out. But for the first time this year he didn't allow a home run, and the end result was that he "outdueled" David Price despite Price pitching better in most objective categories, and the Orioles won 1-0 in extras.
The Orioles' starting pitchers are, on the whole, a below average unit when it comes to getting strikeouts and a slightly below average group at not giving away walks. The major league average K rate for starting pitchers is 18.6% of batters, and the O's starters sit down only 18.1% of their batters faced. They walk 7.9% of batters, compared to the average of 7.6%. In this current little run of extremely good starting pitching, neither of those two facts have really changed.
Tillman, Gonzalez, and Chen combined to walk 7.6% of their 79 batters faced. They struck out 16.5% of their opposing hitters. Those are more or less right in with what the Orioles' starters as a group have done all year. But Tillman, Chen, and Gonzalez also have that shiny 0% home run rate, far below the rotation's total of 3.3%, and very good things have happened indeed.