A quick bit about me, then on to the good stuff. I've been around baseball my entire life, both playing, watching and analyzing. My dreams of being a pro ball player never came true, so I decided to do the next best thing; become absolutely obsessed with the sport. My love for the game, as well as my propensity to analyze things, led me to the silly little game we call fantasy baseball.
My series of Friday posts (this one came a tad bit earlier than scheduled) will be titled "In Ihe Sabermetric Spotlight". Using advanced, rocket-scientist statistics (ok they are actually very simple) to predict where players are headed to give you insight on what to do with them.
This week, the Sabermetric Sportlight is on: Jair Jurrjens, P Atlanta Braves. Is he legit?
Perhaps the most surprising, and impressive starting pitcher in 2011 has been Jair Jurrjens. Before the All Star break, he lead the National League in wins, winning percentage and ERA (12-3, 1.89). Where has this come from? Jurrjens has been a serviceable pitcher (borderline stud in 2009) since 2008, posting decent career marks. Even with 2009 in mind, no one could have predicted the break-out first half Jurrjens had, and if you drafted him any later than the 20th round, you're looking pretty smart right now. Can he keep up this pace (or something similar) for the rest of the season?
Consider this. Let’s say, by seasons end, Jurrjens has a 2.618 ERA over 220 innings, assuming no injuries. That number would be right online with his career low, and might very well lead the league. Any fantasy owner would kill to have those numbers (along with the inevitable 15-18+ wins he'll have). However, the second half might not look as impressive as you would think. The below table will display what I'm referring to.
Add to this discussion Jurrjens' sub-par K/9 rate, and a decent whip, and you have yourself a glorified Doug Fister for the second half of the year. There is nothing wrong with that, but given his current value, it seems as though it's likely to drop. That's all assuming he has a good second half.
That's all well and good, but what evidence is there that his ERA will rise that much, if at all?
Did you know that Jurrjens' Left-On-Base Percentage (LOB%) is at 84.1%? That's higher than any previous year in the bigs and nearly 10% higher than his career mark (not to mention well above the league average). Has Jurrjens been getting lucky? His WHIP would suggest not, but those extra 1 out of 10 base runners that do not score is certainly helping his ERA, right? Jurrjens' Ground-Ball Percentage (GB%) is very close to his career average and lower than his 2008 mark.
Enter BABIP (Batting Average on Balls In Play). This number can be slightly misleading, but it can also explain a lot. BABIP basically measures luck, or lack-thereof. Jurrjens' BABIP in 2011 is lower than any previous year and lower than his career total, but not significantly so. In 2011, Jurrjens' BABIP stands at .256, as opposed to his career mark of .278. This could mean that he has been slightly lucky, or it could mean he is adjusting to hitters very well. Still, the difference here is statistically significant, and much lower than the league average.
This is where a little tool called FIP (or more importantly, xFIP) can become extremely useful. According to Fan Graphs “xFIP has the highest correlation with future ERA of all the pitching metrics.” Basically, FIP is Fielding Independent Pitching (and xFIP being expected FIP). It’s a way to measure a pitchers success taking the variability of the defense behind him out of the equation. This is an extremely useful tool at determining luck and future performance.
You might be surprised to find out that Jair Jurrjens’ first half xFIP (remember, this statistic shows the highest correlation with future performance) is ranked 56th out of 110 qualified pitchers! That’s not elite, that’s not even good…that’s painfully average! His current xFIP is ranked lower than the likes of fellow Brave Derek Lowe, Brewer Chris Narveson, struggling Rockie Ubaldo Jimenez, and the likes of Mike Leake and Chris Volstad. In fact, of the 4 qualifying Braves hurlers (Lowe, Tommy Hanson and Tim Hudson), Jurrjens ranks last.
So Jurrjens is getting lucky? Maybe. Maybe he's developing into one of the best pitchers in the league. On April 18th, Jonny Venters showed Jurrjens a new grip on his two-seam fastball. Given how talented Venters is, maybe Jurrjens improved numbers are genuine.
It's hard to predict future ability based on past performance, especially when you consider the adjustments pitchers and batters make on a daily basis. My opinion (which is just as good as the next guy) is that Jurrjens is at his peak right now. If you can get sub-2.00 ERA value in return for him, it's a no-brainer, you have to do it. Then again, if you are in a keeper league that allows you to keep players based on where you drafted them, and you got Jurrjens in the late rounds, you might consider keeping him at that value.
Questions, comments or suggestions? Hit me up on twitter @SillyLittleGame or leave a comment below!