March 12, 2012 posted by Matthew Dewoskin

2012 Fantasy Baseball Stats You Should Know: SIERA Edition

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Madison Bumgarner, SP, San Francisco Giants

SIERA is hard to understand and ever harder to calculate. It’s so hard to calculate that I can’t post the formula, but it doesn’t matter because no one would possibly be silly enough to try to calculate it on their own.

This is one of the most advanced, complex statistics available. SIERA is advanced physics to ERA’s long division. It’s molecular biology to FIP’s fifth grade science class. SIERA is…really complex. SIERA is short for skill-interactive ERA. It’s a stat that tries to measure how good or poor a pitcher really was without excluding things like balls in play the way FIP and xFIP do.

SIERA tries to explain why certain pitchers can prevent hits and runs while others give them away like free samples at a Dunkin Donuts in Boston. SIERA tells us three things. First, strikeouts are much more important than FIP or xFIP tells us they are. Second, walks are bad, but low walk rates are good. This brought to you from the popular sports blog, “Duh.” Third, balls in play have a lot of variables and it’s difficult to understand what really goes on with them. SIERA tends to favor pitchers with higher than average ground ball rates because ground balls are less likely to go for extra bases and more likely to find their way to a glove of a fielder.

SIERA is presented on a scale similar to ERA, so anything under a 3.20 is great to excellent and anything over 4.50 is pretty awful. SIERA is also park-adjusted, so it accounts for the difference in a pitcher in a pitcher’s park or a pitcher stuck in a hitter’s park.

Josh Collmenter helped a lot of fantasy players with a bunch of wins, a solid ERA and a very good WHIP in 2011. Oh, and he was a complete unknown until he came up to the majors. SIERA claims he pitched way over his head in 2011 and is due for some pain in 2012.

Collmenter managed a 3.38 ERA, but posted a 4.14 SIERA. The large SIERA number was due to his low K-rate (16.1%) and high LD rate (19.7%) and high fly ball rate (47.0%). He actually posted a competent walk rate (only 4.5%), but he was very lucky with a .255 BABIP. Fly ball pitchers should be able to maintain a lower than average BABIP, but Collmenter will be in trouble if that LD-rate doesn’t come down. Collmenter enjoyed a the rare immediate success after a call up and it’s unlikely to continue in 2012…assuming Trevor Bauer doesn’t swipe his rotation spot. Collmenter is also dealing with a forearm issue this spring. It’s not enough to be a red flag, but forearms problems tend to turn into elbow issues and elbow issues mean a visit to ‘ol Doc Andrews.

Some fantasy GMs have a soft spot for Jhoulys Chacin. We really have to wonder why. Chacin was a trendy sleeper pick in 2011 thanks to his 9.04 K/9 in 2010, but his K/9 plunged to under 7.00 in 2011 as he struggled with mechanics all year. However, Chacin’s 4.00+ BB/9 carries over into 2011.

Chacin posted a 56.3% GB-rate, but he also gave up a 15.4% LD-rate. Also Chacin’s BABIP was a crazy low .261. That’s a lot of luck for a guy who gives up bunches of ground balls. The walks and line drives likely fed into Chacin’s 4.08 SIERA. Chacin is waiver wire fodder until he can cut down on walks and get his strikeout numbers closer to his 2010 numbers. Chacin also drew the ire of the Rockies brass by showing up to camp out of shape. Apparently, the Rockies don’t consider “round” a shape.

Part of the reason fantasy baseball pundits are falling all over each other to tout Zack Greinke is his 2.66 SIERA. Greinke posted a high K/9(10.54), a low BB/9(2.36) and really low fly ball rate(30.8%). His 22.0% LD rate is a little high, even for Greinke. He should regress towards his 20.6% career average, but that number is skewed by his poor 2006 season. Greinke’s 2.98 FIP and 2.56 xFIP indicate that he’s a better pitcher than his 3.83 actual ERA and good things could be in store for Greinke in 2012.

Want to irritate the other sharps in your league? Mention Madison Bumgarner and watch their face sour. Bumgarner is another guy that a lot of sharps and pundits are in on and his 3.18 SIERA is one of the stats they’ll point at. Bumgarner showed he can produce solid K-numbers with an 8.40 K/9. He also limited his walks with a 2.02 BB/9. He also owned a 46.0% GB-rate.  Bumgarner posted a lower FIP (2.67) than xFIP (3.10). The lower FIP number is due to his amazingly low 6.2% HR:FB ratio. Bumgarner is worthy of a high draft pick in 2012. SIERA likes Bumgarner and so should fantasy GMs. 


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