SIERA Watch: Day 4 (Data!)

I've created two (separate, but equal) docs -- one in Excel, one in OpenOffice -- for a complete SIERA list, including pitchers who pitched 25 innings or more. You can download these from my Google Docs, here:

Excel SIERA Test


OpenOffice SIERA Test

For those just catching up, here is Day 1 and Day 3 (I was busy on Day 2 with my classes or looking at pictures of cats or something -- doesn't matter, nothing super significant happened).


I just ran a quick little regression or two in STATA. It looks like FIP and SIERA, as a whole, share correlation, but are indeed somewhat different. The chart below shows how they tend to fan out in the higher ranges:

Share this:



  1. Brad, thanks a lot for keeping up on this. I appreciate it. I haven't had a chance to look at the docs yet, but will do so soon.

  2. No problem, mb. I'm happy to do this stuff!

  3. Um...could you tell me what this means? Does this means that Randy Wells' statistic listings were a bit misleading last year? Maybe he wasn't as good as we thought?

  4. Hi Dools! I'm glad you like the site!

    For right now, I don't think we can really say SIERA is totally reliable. Just because it doesn't like Wells, doesn't mean he's not quality. Hopefully we'll nail down where and when SIERA fails, so we can fix it.

    That being said, Wells' xFIP (expected fielding-independent pitching) and tERA (an ERA regression based on how hard the ball is hit -- FB%, LD%, GB%) both indicate Wells enjoyed a pretty lucky 2009 campaign. Expect 175+ innings, decent to good pitching, and an all around, above-average pitcher. He might be an all-star, someday, but not in 2010.

  5. Brad: Lee Panas used your spreadsheet to look at the Tigers pitchers over at I took a look at but I extracted my data from Fangraphs and it differs from yours here. Where'd you get your data from?