Mr. Frustration -- Jake Arrieta in Norfolk

One of the more frustrating Orioles' pitchers over the past three seasons has been Jake Arrieta. Promoted to the Orioles' starting rotation in 2010 after a superficially impressive first half at Norfolk (1.85 ERA in 73 innings, 11 starts), he showed promise in 2010. In 2011 and 2012, he failed to deliver on that promise; his 2012 was especially disappointing. He was the Orioles' opening-day starter, but was demoted to Norfolk in July after going  3-9, 6.20 2012.

When I work a game in Norfolk, I dread it when Arrieta is the starting pitcher; his games seem to take forever because he throws many pitches. At least that's my impression; the rest of this article will look at Arrieta's Norfolk starts I've worked to see if my impression matches reality. I have worked six of Arrieta's AAA starts from 2009; three from 2010; and two from 2012. I will look at those games, hoping to answer three questions — Am I justified in thinking Arrieta works a lot of deep counts; Is there a connection between Arrieta's deep counts and his effectiveness; Has Arrieta changed over the past four seasons?

I consider any at-bat to which a pitcher makes six or more pitches to be a deep count. There can't be a full count unless a pitcher makes at least six pitches, and in 2012 the Orioles averaged just about 3.94 pitches per batter. So, a pitcher making six or more pitches to a batter is making at least 50% more pitches than the average.

Now, let's look at Arrieta's starts for which I have scoresheets:

Date	IP	H	R	ER	BB	SO	BFP	Deep Counts	PCT
6/26/09	6	7	1	1	3	2	26	6	23.1
7/12/09	5.2	5	6	6	3	6	25	6	25.0
7/29/09	6	10	5	5	1	6	28	6	21.4
8/03/09	5	8	4	4	2	4	24	7	29.2
8/29/09	4.2	9	4	3	1	2	25	6	24.0
9/04/09	4.1	4	3	1	6	2	23	9	39.1
4/09/10	5	3	0	0	4	2	20	5	25.0
4/19/10	6	6	2	1	3	5	26	5	19.2
5/20/10	7	4	0	0	2	10	28	7	25.0
8/02/12	5.2	5	2	2	4	5	26	8	30.8
9/03/12	5	3	1	1	1	9	20	4	20.0

Am I justified in thinking Arrieta works a lot of deep counts?
Of course, I don't really know what "a lot" is because I don't have a standard of comparison. However, approximately one out of four batters Arrieta faces is able to work a deep count, and that seems like a lot.

Is there a connection between Arrieta's deep counts and his effectiveness?
Again, we're dealing with a small number of instances, and it's hard to draw hard-and-fast conclusions. There are three starts in which he had significantly more deep counts than normal, and in only one of them could he be considered effective (the start of last August 2).There were two starts in which he had significantly fewer deep counts than normal, and in one he was effective. The evidence is inconclusive, which at least means that there's no obvious connection.

Has Arrieta changed over the past four seasons?
Not based on the games I've seen. Last season, he had one good, almost dominant start and one mediocre start. In his good start, he didn't have many deep counts; in his bad start, he did. There's no evidence to believe that he has learned to become more efficient over time.

Conclusion
There was a lot of hope when Jake Arrieta was moving through the Orioles' system. Since he's reached the major leagues, he's teased us with occasional outstanding games but has generally disappointed. In 2012, he was the Orioles' opening-day starter but was sent down to Norfolk in August. He's listed among the Orioles' rotation options for 2013. Based on what I've seen in Norfolk, both now and in the past, there's no reason to expect anything different from Jake Arrieta in 2013.