Starting Pitcher ERA-SIERA Gaps: Potential ERA Regressers

Yesterday, I listed the 20 pitchers with the largest gaps between their ERA and SIERA marks, with their ERA marks sitting significantly higher than their SIERA marks, suggesting serious potential for improvement moving forward. Today, I’ll list the pitchers on the other side of the coin, the 20 with ERA marks significantly lower than their SIERA marks, suggesting real potential for ERA regression.

Amazingly, only two of the 20 have SIERA marks below 4.00. So that means that the majority of these pitchers might go from valuable fantasy starters to absolutely unusable in a hurry. This is unlike someone who just missed the cut like Alex Wood, whose SIERA, while 0.83 higher than his ERA, still sits at an elite 2.69. Sure, we figure his ERA will rise, but daaaaamn he’s been awesome.

Who would have guessed that at this point in the season, Andrew Cashner of all pitchers would be leading in ERA-SIERA gap?! Heading into the season, his career ERA stood at 3.89, versus a 3.96 SIERA, suggesting he never owned any sort of ability to outperform his peripherals. This season, he hasn’t relied on any one luck indicator, but rather a bit of all three. It blows my mind that he’s struck out just two more batters than he has walked, and yet his ERA is a tidy 3.50.

There’s no doubt that Jason Vargas is getting help from the always sterling Royals defense, but this is actually more about his amazing ability to suppress homers on fly balls and strand baserunners. Over the year, he has shown the skills to keep his fly balls in the park somehow, but that LOB% has no chance of remaining this high. While he will undoubtedly beat his SIERA, that doesn’t mean he’s going to remain a 12-team mixed league asset the rest of the way. I’d personally bet against.

So maybe Ervin Santana’s .208 BABIP isn’t 100% luck, as he has posted the fourth lowest line drive rate in baseball. But at age 34, with the same pitch mix and same velocity, what are the odds he suddenly discovered the secret to preventing line drives from being hit at a league average clip? This is the same pitcher he has always been, but now with more fly balls, which means more homers. I wouldn’t trade very many pitchers for him.

It amused me to see Mike Pelfrey added in both my AL Tout Wars and mixed LABR leagues in recent weeks as it immediately tells me that the owner looks solely at ERA and completely ignores the underlying skills. These are actually the second worst set of skills Pelfrey has ever posted says SIERA, and the ERA is being driven entirely by a career low BABIP.

So much for the first full season in the National League bumping up Ivan Nova’s strikeout rate! Amazingly, it’s actually at its lowest mark since 2011 (excluding his shortened 2014 season). Sure, he has offset the lack of punchouts with sterling control, but that’s not a tradeoff I’d want to see as a fantasy owner. It looks like it’s working now, but that’s all because of a career low BABIP and the second highest LOB% of his career. Given his success when he came to the Bucs last year, he should be an easy guy to sell high on.

Wow, I had no idea Dylan Bundy’s skills were so bad that they fueled a SIERA of 5.00! While his batted ball profile heavy on fly balls and pop-ups suggests he’ll post a better than average BABIP, the Orioles defense has been below average, offsetting some of that. His SwStk% has barely budged, but his strikeout rate has collapsed. It’s due to small declines in his strike percentage, swinging strike and foul strike rates. The big decline in velocity versus last year is another big red flag. I’m waiting for a good time to sell high here.

This might look like a Chase Anderson breakout, but SIERA disagrees. While his strikeout rate is up, his fly ball rate is in dangerous territory, especially given the homer happy league. But despite playing in a hitter friendly home venue, that hasn’t hurt him yet thanks to a suppressed HR/FB rate. He’s never shown any such ability to keep that well below league average, so expect those fly balls to start heading over the wall.

This is now the second season in a row that Michael Fulmer is significantly outperforming his SIERA, and by nearly the same amount. He’s doing it differently though, as this year he’s keeping his fly balls in the park, whereas last year it was a suppressed BABIP and inflated LOB%. This suggests that there’s no magical abilities here that SIERA is missing, but he just keeps getting fortunate in different aspects of the game. He’s a nice sell high in a keeper league where an owner might believe they are acquiring an ace.

Well how do you like them apples? Robbie Ray goes from underperforming his SIERA by 1.31 last year to outperforming it by 0.90 this season. His underlying skills package is largely the same though, with the only difference coming in the luck metrics of course. Amazingly, despite posting the second highest Hard% in baseball, his BABIP has tumbled well below the league average, and dropping from an absurd .352 last year. And then he’s stranding everyone, when he’s never shown such ability in the past. So basically, this is the same pitcher, but he’s a perfect example of why over one season, SIERA has far more predictive value for year two than ERA does.