Detroit Tigers Analysis

Five Aces

Rick Porcello's growth gives the Tigers five dominant starters

By John A McGeehan Jun 5, 2013, 8:14am EDT

Rick Porcello, a top ten starting pitcher

The stat geeks have many formulas for measuring the effectiveness of pitchers that go beyond ERA. They look at FIP, xFIP, WHIP, BABIP, and even stats that do not rhyme. But one that some consider to be the best measure of how well a pitcher has performed is SIERA, Skill Independent Earned Run Average. It tries to remove some of the luck that can distort an ERA. For instance, a pitcher allows a bunch of seeing-eye ground ball singles or five home runs into the first row of seats. Going forward he could pitch the same and more of the ground balls would be outs, and some of the home runs would be caught at the wall. If you want the gory details, take a look while we wait.

A digression - in Little League I use "RA/6" (runs allowed per six innings) to measure the effectiveness of pitching. Trying to separate earned from unearned runs is a fool's errand, and using a full game rate of six innings allows for a lower result. An RA/6 below six is an ace!

So after another typical dominating performance by a Tigers' starter, let's look at the starting pitchers in all of baseball and sort them by SIERA. Yu Darvish rises to the top. Striking out 12 per nine innings without a bunch of walks is a strong path to a Cy Young award. Anibal Sanchez is second. Max Scherzer is third. Doug Fister is sixth. Justin Verlander, having an off year, is fourth on the team but still ninth best among all of the major league starters. And rounding out the top ten? Rick Porcello. Rick has always had a high ground ball rate, but by increasing his strikeout rate to 7.4 per nine innings he is moving from being a fifth starter to being an ace.

Looking at this another way, there are five teams that have an ace better than the Tigers' number five starter. Felix Hernandez, Adam Wainwright, Matt Harvey, and Alex Cobb rank in the top ten by SIERA. But you must look below Porcello into spots 11 to 30 to find Chris Sale, Stephen Strasburg, Clayton Kershaw, Jake Peavy, Cliff Lee, James Shields, and CC Sabathia.