By The Numbers: Carlos Carrasco, Tyler Mahle, Chris Bassitt (2022 Fantasy Baseball)
The sabermetric statistic SIERA stands for Skills Independent ERA. SIERA attempts to narrow ERA down to what is purely in the pitcher’s control.
The goal of SIERA is to try to figure out the true skill of a pitcher, so the formula for SIERA factors in a pitcher’s strikeout, walk, and groundball rates. It also accounts for the type of balls that get put into play and adjusts for the result – meaning pitchers that are ground ball and fly ball heavy are rewarded because those types of hits result in outs more often than line drives.
SIERA also rewards pitchers who may not induce many strikeouts but limit walks or induce ground balls.
Because other advanced ERA metrics like FIP and xFIP do not account for the type of ball that gets put into play, many consider SIERA the most accurate and predictive of the advanced ERA metrics. This also makes SIERA a valuable statistic for finding pitchers to buy and sell.
From this list, only Fried and Skubal are outside the top 10 in K/9. McClanahan, Nola, Gausman, and Fried are among the best in BB/9. McClanahan and Gausman are among the best at inducing grounders, and it is no wonder these players have the lowest SIERAs.
Today, this column will help fantasy baseball managers find “buy low” pitchers by looking at the difference between a pitcher’s ERA and his SIERA.
Carlos Carrasco (SP – NYM) 3.63 SIERA
Carrasco has a 4.85 ERA, sixth-worst among qualified starters, but his SIERA is over a run better. It is the fourth-largest gap for players whose ERA is worse than their SIERA.
Carrasco is doing many things well, especially regarding SIERA’s formula. He has an 8.9 K/9 rate and a 2.3 BB/9 rate. His 20.8% line drive rate is Carrasco’s lowest since 2016, and his 45% groundball rate is his highest since 2018. He also suffers from the third highest BABIP in baseball among qualified starters.
Additionally, the righty has the second-best chase rate at 39.4%, behind only Kevin Gausman.
All of these factors imply that his ERA does not reflect his true talent or what his ERA should be. A significantly better SIERA makes Carrasco an excellent target to buy for the rest of the season.
Tyler Mahle (SP – CIN) 3.77 SIERA
Mahle has many similar background metrics to last season. He has a nearly identical K/9 rate of 10, and his BB/9 rate is .10 walks per nine innings higher this season.
Last season Mahle had a .297 BABIP compared to a .300 BABIP this season, although he shaved 2% off his line drive rate, suggesting that his BABIP should probably be lower than it currently is.
One of the biggest issues driving his ERA up is a lower-than-usual 66% LOB rate, largely the fault of a poor defense. The Reds are among the worst in putouts, defensive runs saved, and overall defensive WAR, according to Fangraphs.
The righty also has a 34% groundball rate versus a 42% rate from last season, which can improve throughout the season.
Some positives for Mahle include a fastball, splitter, and slider, each with a whiff rate over 25%. His fastball, cutter, and changeup all have a lower expected batting average against than BAA. Plus, he is likely to be traded to a contender before the deadline, making him a prime candidate for positive regression and a great player to acquire right now.
Chris Bassitt (SP – NYM) 3.50 SIERA
Bassitt’s 4.01 ERA is not terrible, but his SIERA suggests he could and should be doing better.
He has a 9.5 K/9 rate, the best of his career. His 2.61 BB/9 rate is better than the league average. His 46.1% groundball rate is his highest total since 2016, when he only pitched in five games. Furthermore, Bassitt has allowed his career’s lowest line drive rate at 15.8%. Each of these data points is a factor in the formula for SIERA, which is why it is about a half-run better than his ERA.
The righty also has a .278 BABIP, just .002 points lower than his career average despite a major improvement in line-drive rate (a vital connection explained here: https://www.fantasypros.com/2022/06/by-the-numbers-j-d-martinez-cesar-hernandez-corey-seager-2022-fantasy-baseball/). Along with some positive regression to BABIP, Bassitt is also due for positive regression to a 14% HR/FB rate, which is above both league average and his career average.
Bassitt is another excellent candidate to try to acquire now before he improves and his value goes up.
If you want to dive deeper into fantasy baseball, check out our award-winning slate of Fantasy Baseball Tools as you navigate your season. From our Lineup Assistant – which provides your optimal lineup based on accurate consensus projections – to our Waiver Wire Assistant, which allows you to quickly see which available players will improve your team and how much – we’ve got you covered this fantasy baseball season.