Troubling Trends for Blackburn and Slowey

Over the next two days, Twins fans will be watching Nick Blackburn and Kevin Slowey take the hill against the Detroit Tigers, with the lead in the AL Central hanging in the balance.

I'll give you a moment to reach for some antacids.

Blackburn and Slowey have had a rough time of it in 2010.  Nick currently sports the highest ERA in baseball among qualified pitchers, along with the second highest FIP.  Slowey has been steadily declining, posting a 3.77 ERA in April, a 4.55 ERA in May, and a 6.15 ERA in June.

Yes, things are bad in the back end of the Twins rotation.  Let's take a closer look:

Nick Blackburn

Going into today's game, Nick Blackburn has struck out 2.94 batters per nine innings this season.  That's bad.  I mean really, really bad.  It's easily the lowest in the league (among qualified pitchers).  But just saying that doesn't do it justice: the next lowest K/9 is owned by Aaron Cook of Colorado who's struck out 3.97 batters per nine- a full point higher than Nick's current rate. 

In fact, it's so bad that I thought I'd try to put it into a little historical perspective.  Using the Lahman Database, I looked at pitching seasons from 1945-2009.  In that time, there were 8,101 instances of a pitcher throwing 100 innings or more in a season (I used 100 IP as a completely arbitrary cutoff point, just to eliminate small sample sizes).  Of those 8,101 pitcher seasons, there were 395 times when a pitcher finished the year striking out fewer than three batters per nine innings.  That's 4.5% of pitcher seasons.

But, as we know, strikeouts have risen pretty steadily in the past several decades.  If we look at a more modern sample - 1990 through 2009 - Nick's strikeout rate looks even more troubling.  Since 1990, there have been only 15 cases of a pitcher hitting the 100 inning mark and finishing a season with fewer than 3 strikeouts per 9 innings.  That's out of a total 2,705 pitcher seasons.  That's about one half of one percent.

Interested in seeing the company Nick is keeping?

Looking at that chart, it's obvious why there are so few pitchers that met the 100 IP, less than 3 strikeouts-per-nine mark: it's nearly impossible to be a big league starter when you're striking out so few batters.  The only full-time starter on the list who posted an above average ERA was Kirk Saarloos in 2005, who won 10 games for the A's.  Kirk's 4.17 ERA looks pretty fluky, though, given the fact he walked more men than he struck out and posted a 4.47 FIP and 4.67 xFIP.

No, I don't think Nick is going to finish the season with a sub-3 K/9 rate.  He's career average is north of four and, well, it's just really rare to see a pitcher do what Nick is doing right now.  That being said, there is no ignoring the way these numbers are trending:

This is bad news, no matter how you look at it.

Kevin Slowey

Kevin Slowey's biggest problem hasn't been his strikeouts.  Even though his K rate is a bit off his career mark, he's still posting a very good 3.47 strikeout-to-walk ratio (15^th best in the majors, but, amazingly, 4^th best in his own rotation).  No, Slowey's problem remains what it's always been: too many fly balls, too many long balls.

Slowey's groundball rate is dead last among qualified MLB starters.  His fly ball rate is the highest in baseball at 51.8%.  No qualified pitcher has finished a season with a fly ball rate that high since 2007.  It's not that a lot of his fly balls are going over the fence - his HR/FB is at 9%, a bit below league average.  But when half the balls put into play against you are fly balls, you'd have to be extremely lucky not to give up a ton of home runs.

Slowey's troubles with fly balls are nothing new, but they are getting worse (via Fangraphs):

Much like Blackburn, Slowey has seen his biggest flaw become even more glaring over the past few years. 

Conclusions

I don't have a whole lot to add the numbers.  The back end of our rotation is anchored by one guy with the worst strikeout rate in baseball, and another with the worst groundball rate in baseball.  Considering striking hitters out and keeping the ball on the ground are two of the most important things pitchers can do to be successful, there is no sugar coating those facts.

The good news is that both of these pitchers have solid track records, both are in their prime, and both could start bouncing back as soon as today. The flip side, as we've seen, is that these bad numbers are part of troubling trends stretching back over the past few seasons.

How about some good news for a change?

I'm not trying to be all doom and gloom, I promise.  We've come home from a tough road trip and gave up first place last night.  But before anyone starts writing a post-mortem on the Twins season, let's remember this:

2010 Run Differential, AL Central

Yes, I know baseball isn't played on paper.  Yes, I know teams over-perform and under-perform their run differentials every season.  Yes, I know all that matters is wins and losses.  But I truly believe these numbers mean something.  And I truly believe we're still the best team in the AL Central.