Hi guys, longtime lurker here. Finally decided to dive in to the commenting and posting ranks this summer. First post, so bear with me. Also, I wrote this up before yesterday’s bizarre (yet expected) Guthrie performance. I think his performance yesterday actually lends nicely to this post.
Disclaimer: I have no idea if any of this is useful analysis, but I found it interesting. Feel free to rip into anything I say that doesn’t make sense or is founded on unsound understanding or logic.
This all started when I had a question about LOB%. A lot has been made of LOB% around here because of Jeremy Guthrie’s 85.9 LOB% (99.2%!!!!! against left-handers) against the league average of 73.1%. Before doing some research I always assumed LOB% was calculated through a straightforward “strand rate” like:
After checking with Fangraphs, I found out the formula is actually:
The only thing added (subtracted in the formula) is the 1.4*HR. Hardball Times says they “exclude home runs from the base because [they] want to measure things a pitcher is less likely to control”, a sort of a confusing statement. Can anyone better explain to me why the HR is included in the formula?
I was then curious how Guthrie’s high HR rate was contributing to his high LOB%—if at all. By my calculations, if Guthrie had a HR/FB at his career rate 10.9% with his current Runs Allowed, his LOB% this year would be around 80.5%, still ripe for regression. I also realize this is pretty arbitrary because if you lower his HR rate, that would lower the number of runs he’s given up on the season, so I’m essentially raising the denominator, when in all likelihood I should raise the numerator as well. But I’m guessing an inordinate amount of Guthire’s RAs are coming from the long ball so this isn’t completely fruitless.
Let’s look at his start from 5/14 against the Angels.
He pitched 7.0 innings, gave up 11 hits, 3 walks, 5 runs and 4 HRs (with 0 Ks to boot). For those scoring at home, that would leave him with a LOB% of 107%. WTF. It seems that when looking at a guy with Guthrie’s HR profile, LOB% may not be super useful, at least on a start-to-start basis. It seems counterintuitive that a guy could have an ERA of 6.43 on the night but have a LOB% of 100%. But nonetheless, moving forward I expect him to start giving up fewer homeruns, and when he does give them up, I expect there’s going to be men on base more often. Currently with no one on base his HR/FB is 21.1% against 7.9% with men on base. As his HR/FB goes down, I think the number of runs he gives up not via the homerun is going to increase markedly, potentially offsetting some of the decrease in LOB% due from lowering his HRs. I think it is totally conceivable that Guthrie’s LOB% will appear to be “unsustainable” for the rest of the season.
Now Jeremy Guthrie is giving up A LOT of home runs (see yesterday evening). He has a HR/FB of 15.5% and for someone with a career FB% around 40% this should be very problematic. League average HR/FB this year is 10.8% right in line with his career average of 10.9%. Guthrie’s career high HR/FB, 13.5%, came last year while splitting time between Coors and Kauffman. Over the rest of the season, I expect his HR/FB to regress from the 15.5% even if it’s something closer to last year’s rate.
The peripherals he can supposedly control aren’t good. He sports a career low K/9 and a career high BB/9 all leading to a FIP of 5.64 and xFIP of 4.89. Yikes. I’m going to look at the xFIP here, because as I understand it, xFIP accounts for instability in HR/FB rates and uses league average HR/FB in the formula. So in theory, it should offer a better look at what Guthrie will look like as his HR/FB rate improves.
Guthrie is going to regress—that’s not the question. The question is when, and how hard. His 2013 BABIP is .261 against the league average of .293. His career BABIP is .275 compared to the league average of .295 during this same stretch. So even if he continues to outperform league average BABIP at his career norm, his current BABIP on the season can be expected to jump up. It seems that some of Guthrie’s bad peripherals are offset some by his BABIP consistently outperforming league average. Playing in front of a pretty good defense may help.
Over his 6-year career as a major league starter, Guthrie’s ERA has been known to outperform his xFIP. In 2008 with the Orioles his ERA was .85 lower and in 2010 his ERA was .77 lower. Before this season, his career ERA beats his career xFIP by an average of .38, not an insignificant number. For comparison, someone like Matt Cain has had their career ERA outperform their xFIP by .83 points. After yesterday, Guthrie is currently outperforming his xFIP by 1.3. If his 2013 ERA outperforms his xFIP at his career average rate of 38 points his ERA would be 4.64. Assuming he has 18 starts left and continues to pitch consistent with his first 14 starts, he would have to pitch with an ERA of 5.36 the rest of the way to settle in at this adjusted ERA. Even if he outperforms his xFIP by his career high of 85 points, he would have to pitch with a 4.52 ERA the rest of the way to settle in at that adjusted ERA of 4.17. This is going to get ugly—even more so if that HR/FB doesn’t regress like I’m counting on.
Of course, this could just be that random year where he’ll continue to pitch poorly and get good results. But I’m not betting on it, and even if it is that random lucky year, the thought of the regression he’d be due over the next two years—at $11 million and $9 million mind you—should keep you up at night.
After yesterday’s performance, his ERA rose to 3.72, his xFIP rose to 5.02, his BABIP dropped 5 points to .256, LOB% rose to 86.1% and—thanks to 3 of his 11 fly balls going over the fence—his HR/BB increased to 16.7% with a HR/9 of 1.86. These are not the regressions you’re looking for. I feel like I need a Golden Tablet to decipher what is going on with his season.