Porcello had a promising spring training replacing his ineffective slider with a curve and showing an improved change-up. Fans once again became impatient with the right hander though when he got off to a sluggish start and skepticism turned to grave concern when he allowed nine runs in the first inning on April 20 versus the Angels. With his ERA now up to 11.08, disappointed fans could not understand why the Tigers kept putting him out there while Smyly was seemingly being wasted as a long reliever. Even Porcello's most loyal followers were beginning to wonder if he would ever take the next step forward.
Since that abysmal start versus Los Angeles, Porcello has posted a 2.84 ERA and fantastic 56/10 strikeout to walk ratio over nine starts and 57 innings. This is by far the best stretch of his career and the only time he has shown any consistent ability to strike batters out. For the season, Porcello has struck out a career best 7.6 strikeouts per nine innings. That is a remarkable improvement over a 5.5 strikeout rate in 2012 and 5.2 for his career. This is no fluke - strikeout rates do not improve by two per game over 70 innings by accident.
Porcello has not sacrificed anything to increase his strikeout total as his walk rate (1.7 per nine innings) and ground ball rate (56%) are also career bests. His ERA is only 4.37, but that is mostly because of the one awful start. Take away that one game and his ERA is 3.26.
So, Porcello is experiencing sustained success for the longest period of his career, but we have to dig a little deeper to understand why. The top theories as to why he is doing better are:
- Less reliance on sinker
- Adopting the curve as his primary breaking pitch instead of a slider
- An improved change-up
Brooks, suggests why his curve is better than his slider. While the slider was very straight, the curve has quite a bit of horizontal movement, especially this year. I'm not sure how much that is driving the results, but the numbers are excellent. Last year, his slider was tattooed for a .410 batting average and .638 slugging average. This year, batters have hit his curve at a very reasonable .238/.416 clip.
Figure 3 gives us a clue as to the effectiveness of his change-up. The Whiff Percentage (or percentage of change-ups that result in a swing and miss) has increased each year, with the biggest jump coming this year (13% in 2012 to 16% in 2013). You'll notice that the Slider Whiff Percentage is also up, but you can probably ignore that as he rarely throws it this year. Anyway, the more effective change-up is showing up in the results. Last year, he allowed a .250/.410 BA/SLG on change-ups. This year it's down to .215/. 308 and he has almost as many strikeouts on change-ups (17) as his trusted sinker (18).
Figure 4 shows where all the ground balls are coming from. The ground ball rates on his sinker (60% in 2012 to 70% in in 2013) and curve ball (43% to 63%) have both increased substantially.
There are not a lot of fans asking for Porcello to be traded anymore and those that still want a trade are demanding much bigger returns.