Friday, April 18, 2008

High and Dry

A useful metric to use when analyzing pitcher performance is strand rate (or LOB%). Strand Rate is the percentage of runners that reach base and do not cross home plate. The average starting pitcher’s strand rate is usually around 70%-72%. There is some debate on whether or not strand rate is a matter of luck or if it is a repeatable skill, but it is clear that good pitchers tend to maintain higher than average strand rates.

Strand Rate = (Hits + BB + HBP - R)/((Hits+ BB + HBP -(1.4 * HR))

Early in the year it is difficult to draw too many conclusions about strand rates. For example, Zach Greinke’s strand rate through his first 3 starts is 97.1%. That number will come down but it doesn’t mean that Greinke is due to get rocked.

We can, however, gain a little bit of information by looking at pitchers that have a poor strand rate through their first few starts. The pitchers listed below will likely see improvement in their ERAs because base runners will soon start to be left high and dry at a greater clip. You might be able to pry a few of them from their panicky owners at less than face value.

The statistics next to each pitcher are their 2008 LOB%, their career LOB%, and their 2008 ERAs.

Justin Verlander 35.1% vs. 75.9%, 6.52
A.J. Burnett 60.3% vs. 71.5%, 7.27
Johnny Cueto 62.5% vs. N/A, 3.22
James Shields 62.5% vs. 72.1%, 3.52
Tim Hudson 63.1% vs. 73.3%, 3.38
Gil Meche 65.1% vs. 71.6%, 6.08
Roy Oswalt 65.6% vs. 76.9%, 6.65
Ian Snell 66.5% vs. 73.3%, 3.93

The numbers above tell different stories for each pitcher. It should be clear that Verlander, Burnett, Meche and Oswalt have been a little unlucky with their base runners. If their respective strand rates improve to just the league average they will each see sizeable improvements in their ERAs. All of the above look like buy low candidates based on this metric. Note: My pre-season AL CY Young pick, A.J. Burnett, is looking like a long shot right now. However, I fully expect his ERA to take a dramatic turn south in the next month, and his current strand rate is one reason why.

Johnny Cueto is an interesting case because he is a rookie. Most people would expect Cueto to go through some rough stretches ahead, therefore it is difficult to suggest his already fine ERA will improve due to an increase in strand rate. We’ll have to wait and see how Johnny C’s strand rate fluctuates and how that affects his ERA. It may turn out that he is they type of pitcher that maintains merely a league average strand rate.

Shields, Hudson, and Snell all have respectable ERAs right now, despite the fact that each of them is sporting a LOB% roughly 7 - 10 percentage points lower than expected. Their ERAs are good enough such that their owners will probably not part with them for less than face value. If you own them, enjoy the correction that will be coming shortly in your favor.

We’ll revisit these arms next month to see how their ERAs look as their strand rates move closer to their expected ranges.


Brett Greenfield said...

Good Stuff boys...

I hope whoever has Conor Jackson in the league started him this week.

Chris said...

Bremen is reaping those benefits. But he's also suffering with Pence and Soriano in the OF.