Starting Pitcher ERA-SIERA Gaps: Potential ERA Improvers

We’re nearing the midpoint of the season (wow has it come quickly!), so it’s finally time to check in on the starting pitchers whose ERA marks are significantly higher than their SIERA marks. Naturally, many on this list are bad, even after figuring in some improvement, but there are enough potentially good pitchers that would make for actual fantasy targets. So let’s discuss them. For completeness purposes, I’m listing the entire top 20, but will only discuss those that matter.

One of my best friends asked me if he should pick up Josh Tomlin because his SIERA is so much lower than his ERA. I told him that this is true, but even his SIERA is unimpressive, so don’t touch him! He plays in a shallow mixed league, so there’s no reason to ever pick up a low strikeout, 4.00+ SIERA guy, even if you think his ERA is due for improvement.

Man, has Masahiro Tanaka done his best Jekyll and Hyde impersonation or what this year?! Going back eight starts, his runs allowed have looked like this: 8, 6, 1, 7, 5, 1, 5, 0. He continues to post strong peripherals, but his fly balls simply won’t stay in the park. His HR/FB rate is highest among all starting pitchers in baseball, and that’s bound to regress. Obviously, he plays in a hitter friendly venue and home runs at being hit at an historically high clip, so it would be silly to expect a league average mark moving forward, but there’s no way his true talent level is over 20%. This is also the first time his BABIP has pushed above .300, which is bizarre considering the Yankees rank fourth in baseball in UZR/150. I just don’t see any reason to believe he won’t post a sub-4.00 ERA moving forward.

I would be a little more excited about Trevor Bauer’s strikeout rate surge and second half breakout potential if that strikeout rate spike appeared legitimate. Actually, his xK% does suggest that what he has done so far is real, but the strikeouts are being driven by a jump in called and foul strikes, while his swinging strike rate has tumbled to a career low. That’s no good and makes it hard to believe he can sustain the strikeout rate, as it requires inflated marks in rates that are less consistent. So what this all means is that Bauer doesn’t appear to be that much different a pitcher than always, despite a career best SIERA. While I certainly expect improvement, don’t get too excited about a buy low opportunity given the lofty strikeout rate.

In June, Jeff Samardzija has struck out 28 batters and walked just two over 26.2 innings. How does he get rewarded? With a 5.06 ERA, of course. In May, he posted an incredible 49/1 K/BB ratio over 40.2 innings, but his ERA was only 3.32. He’s getting no support from his defense, which register just barely positive UZR/150 value, while he cannot keep the ball in the park when he pitches in away games. To really kick fantasy owners when they’re down, he’s received the seventh lowest run support among 76 starting pitchers in baseball. He will probably come cheaply in the vast majority of leagues, so go ahead and trade your Jason Vargas straight up for Samardzija.

On Friday, Jeff Zimmerman tried to answer the question of what has gone wrong for Rick Porcello. It’s really simple and could be summarized with just one number — .371. That’s Porcello’s absurd BABIP, which is second highest in baseball (amazingly, not the highest mark!). Heading into the season, Porcello’s career BABIP stood at .307, so he hasn’t exactly been a hit suppression master. But .371 is what would happen to a little league pitcher trying his craft in the Majors, not an established veteran, especially one coming off a Cy Young award win. He has posted a career high fly ball rate, but that would normally reduce BABIP, not increase it, and while his LD% is up, it’s still only marginally higher than the league average. The Red Sox defense has been fine, ranking ninth in UZR/150, but if we check his Hard%, we find a crazy 43.2%, wayyyyy higher than any of his previous seasons. And yes, that’s highest in baseball. So we note that batters are hitting Porcello’s pitches harder than ever before, which partially explains his high BABIP, but we don’t know why. That’s the $100,000 question folks!