SIERA for Pitchers - Daily Fantasy Sports
Posted on Apr 3rd, 2012 09:08 AM
ERA (Earned Run Average) is the most popular and traditional measure of a pitcher’s performance. It tells you how many earned runs a pitcher has allowed on average per 9 innings pitched. The stat is inherently flawed as a measure of an individual pitcher’s performance by its very definition. It tells you what happened when a certain pitcher was on the mound, but does not factor in a pitcher’s true talent or give you of an idea of how he’s likely to perform going forward. ERA becomes even less valuable when a pitcher changes teams.  At the end of a long career, you can probably look back at a pitcher’s ERA and say, “Yeah, that’s what he was”, but that doesn’t help you much in Daily Fantasy because you want to know how he’s likely to perform in his next start.

Enter FIP (Fielding Independent Pitching), which attempts to remove the 8 other players on the field from a pitcher’s results. It focuses on the 3 true outcomes (BB/HBP, K’s, and HR’s) to better assess a pitcher’s performance, while removing balls in play from the equation. Skeptics, though, refuse to believe that a pitcher has so little control over batted balls.

One of the biggest problems with FIP is that it uses a pitcher’s actual HR/FB for the season it is measuring. These rates are highly unstable from year to year. Dave Studeman attempted to fix this problem with xFIP (expected Fielding Independent Pitching) by employing league average HR/FB rates and a pitcher’s own fly ball rate to remove some instability. 

Still, neither FIP nor xFIP allows for the possibility that pitchers may have some control over their batted balls. Enter SIERA or Skill Inter-active ERA.  SIERA is similar to xFIP, but explores the possibility that inducing weak contact and/or avoiding HR’s may be a skill. It’s possible that pitchers play a larger role in their own BABIP than they are given credit for. SIERA also adjusts for park and run environment, making it easier to compare players across the board. Recent trials lend credence to SIERA and suggest that it may be one of the best tools currently available for estimating a pitcher’s future results.

As we get into the 2012 season you’ll notice that SIERA is a favored metric in reUP Sport’s Daily Fantasy Starting Pitcher Analysis.  Let’s take a look at the pitchers who had the largest gap between SIERA and ERA last year and ponder what may lie ahead for each in 2012.

SIERA Under-Performers

Here are the 10 pitchers whose ERA underperformed when compared to their SIERA by the largest margin in 2011. As with the BABIP series, it’s best to think in terms of over or under-valued rather than good or bad when considering these gaps.SIERA Under-Performers 2011

Brandon Morrow (3.31 – 4.72 – 1.41): His SIERA has beaten his ERA by over a run in each of the past 2 seasons and for his career. He also struggles mightily with men on base. Over a season or two, these things may be considered random variance. However, the longer it goes on, the more credence must be given to the actual results. He also pitches in one of the tougher parks in one of the toughest divisions. Morrow has all the “stuff” in the world (25.7 K%, 11.2 SwStr% career). In fact, he’s like no other pitcher of the past 20 years in some respects. On sites that value K’s very highly, he may be worth the risk, but if he doesn’t put it all together soon, he may be one of those outliers who never does reach the potential his peripherals imply.

Derek Lowe (3.75 – 5.05 – 1.30): Lowe is a ground ball machine (2.62 GB/FB last year) and needs a strong defense behind him. The Braves were 5th worst in the majors with a -23.2 UZR last year. Even worse news, the Indians were 3rd worst at -47 UZR. He deserves better, but it looks like he might be in for another long year.

A.J. Burnett (3.89 – 5.15 – 1.26): Like Morrow, tough park in a tough division led to a horrific 17% HF/FB rate. He was 20th in the majors with a 10% SwStr rate though. The move to Pittsburgh should help him immensely. Once he returns from injury, Burnett could be a greatly under-valued pitcher this year. I envision buying low on him quite a few times.

Zack Greinke (2.66 – 3.83 – 1.17): Greinke is saber darling #1. His SIERA led the majors in 2011, but he had a little problem with bunched hits. He was one of those “one bad inning” guys. The Brewers have an almost entirely new infield defense this year, but not necessarily an improved one. It’s possible his issues could have been as much mental as anything else with moving to a new team and city, considering his history. For this reason, it’s smart to be cautious, but Greinke may be the most under-valued pitcher in the league. He can run out another ERA close to 4 or win a Cy Young this year.

Fausto Carmona (4.18 – 5.25 – 1.07): Fausto Carmona is no longer Fausto Carmona. It even sounds like a made up name when you think of it. He certainly wasn’t very good, but he wasn’t that bad. I don’t even think he’s in the country right now. Derek Lowe, welcome to Cleveland. This may be what you have to look forward to.

Chris Volstad (3.84 – 4.89 – 1.05): No doubt the firm of Epstein and Hoyer took notice of this discrepancy when picking him up. The Marlins are particularly atrocious defensively and have been for years. Unfortunately, the Cubs may not be much better and he’s going from a pitcher’s park to a hitter’s one. That said, he did have his best K (16.3%) and BB (6.8%) rates of his career last year. He has a HR problem (12.3 HR/FB%) and an issue with men on base throughout his career though, so don’t get too excited. However, there is a chance he’s actually not a terrible pitcher.

Ryan Dempster (3.79 – 4.80 – 1.01): His BABIP (.324) was .021 higher than his career level. Nothing else in his batted ball profile or peripherals changed all the much. Believe it or not, his 2011 SIERA was actually the 3rd best of his career. We know Ryan Dempster is not a bad pitcher. If he’s priced based on last year, rather than his career, there’s value to be had here.

Chris Capuano (3.60 – 4.55 – 0.95): Capuano pitched his 1st injury free season since 2006 last year. He seemed to solve his problem with RHB and had the highest K% (21) of his career. He’s a flyball pitcher with a HR tendency (12% HR/FB 2011) that could have been even worse if not for his home park. Dodger stadium isn’t a bad pitcher’s park, but it’s not Citi Field. The Mets may have also had the worst defense in the majors last year.

Ubaldo Jimenez (3.74 – 4.68 – 0.94): Ubaldo held solid K (21.9%) and BB (9.5%) rates, but saw his BABIP (.314) jump .028 points above his career average. His problem lies in a 2 mph loss in velocity which led to less infield flies (6%) and more HR’s (9.3 HR/FB% LY – 7.7% career). Re-found velocity would be cause for optimism, but here’s another GB pitcher in front of the previously maligned Cleveland defense. While Jimenez may have a chance at a bounce back in 2012, keep in mind that he had a large SIERA/ERA gap (0.80) in the opposite direction in 2010. He may be more of a solid #2 than an Ace if everything evens out. Keep an eye out for more concerning pitchers with velocity dips who struggled in 2011 coming soon.

Ricky Nolasco (3.79 – 4.67 – 0.88): Nolasco is someone who has consistently under-performed against his peripherals for years now. He’s already at where Morrow may be headed. There is again the matter of the Marlin defense, but at this point, the reality of the situation must be considered. Sometimes a pitcher is what he is.

Best Bets to Rebound: A.J. Burnett, Zach Greinke, Ryan Dempster

Best Bets to Continue to Under-perform: Derek Lowe (defense), Ricky Nolasco……eh, Brandon Morrow. I would add Fausto Carmona, but that person no longer exists.


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