Going into the season, I was not necessarily worried that Michael Wacha would pitch badly. I was worried he wouldn’t pitch at all. That worry is perhaps overstating his actual injury problems. He had missed time in three of his five full seasons, but made 24 starts in one of those seasons and 15 and 19 in the other. He put together 30 start seasons in 2015 and 2017, both of which are fair to say are his best two seasons. (The only other competition is his shortened 2014 season, which is probably his best season on a rate basis.)
Needless to say, this season has shocked me. He has been stunningly bad. He has a career low K%, a career high BB%, and the juiced ball has given him a 22.1 HR/FB% on the year. Even when he’s cobbled together a good start, he just doesn’t look good either. He seems to generally not really know where the ball is going, throwing plenty of pitches out of the strike zone and too much in the strike zone. He has a 5.22 ERA with a worse FIP (5.80) and a 5.20 SIERA.
However, he has intriguingly had good starts the past two times he’s pitched. He hasn’t been asked to do much - he exited Tuesday’s game after just 4 innings and he only went 5 innings in the other start. You would like him to go more innings, but he’s also the 5th starter at this point, and that’s pretty much what you want out of your 5th starter in 2019. (Also him only lasting four was definitely not his fault) Pitch at least 5 innings, allow between 2-3 runs, and give it to the bullpen. Especially with a bullpen that has been as good as the Cardinals bullpen has been. Jack Flaherty, Miles Mikolas - they can eat innings. Wacha merely needs to make sure the offense doesn’t have to have a spectacular night in order to win, which tended to be the case in most of his starts this year.
I was curious if anything had changed in his last two starts that would make us believe he could be a better pitcher going forward. The theory goes, a different approach, a different pitch, different velocities - these are the kind of things that you need to believe a pitcher’s improved stats reflect a genuine improvement. If nothing has changed, it’s hard to buy into two good games. It’s generally hard to see if a pitcher is pitching good or if the offense just isn’t hitting hittable pitches. Over a longer sample, you can determine that but in two games, not so much. So I’m looking for a change.
And I found one. It’s a relatively simple change, a knock yourself on your forehead “Duh” on what pitchers should do. He’s throwing his best pitch more. Simple as that. Wacha has been known for his changeup since he was drafted and it can be a lethal pitch. From the batter’s eye, it is indistinguishable from his fastball when it comes out of his hand, which makes it hard to square up or even hit. Here’s his changeup usage by month.
If you’re wondering why his change usage was so low in his first four months of baseball, it’s because it wasn’t. Just look at his career change usage.
That obviously does include August, so his change usage would be lower if we excluded that month, but I’m sure it would be hovering around 2017 and still be above both 2014 and 2015. It’s curious that his change was used so little in some of these years to me. Get to two strikes and then throw the change appears to have been the idea. Once you understand that, the change usage makes more sense. Anyway, 2019 overall fits in pretty well with his career, with the exception of his ridiculous run in 2013.
Here’s the problem though. A fastball and cutter heavy approach works great... if they’re effective. From 2013-2018, Wacha’s fastball has been a net positive pitch, producing a fastball that was 18.1 runs above average. His cutter has been less successful, producing 3.2 runs below average during that same timespan. Last year his fastball was 2.9 runs below average but his cutter picked up the slack, with 5.5 runs above average. He has thrown a fastball or cutter over 68% of the time throughout his career. So the fastball/cutter heavy combination has been very successful for Wacha.
Not so much this year. His fastball has been -8.1 runs below average, which is tremendously bad. His cutter did not pick up the slack, being worth -5.5 runs below average. As a whole, the fastball/cutter combo has never been negative value for Wacha, but this year it’s 14.3 runs below average. His change has been +5.9 runs above average this year.
So before the last two games, Wacha had thrown a season high changeup usage of 27.8%, which he did twice, once in June and once in May. He threw 32.5% of changes in Cincy and 30.1% on Tuesday. He has thrown his changeup on average 21.8% of the time this season, so I think it’s fair to say that throwing over 30% changeups is a change in approach. He has also significantly cut down on his cutter usage, which started against the Dodgers.
This is the smallest of small sample sizes, but Wacha’s increased changeup usage, at least so far, has cost him the effectiveness of his changeup but making his other pitches look better. His change has been 0.1 runs above average the last two games. His fastball has been worth +2.1 runs above average and his cutter has been -0.1 runs below average. His curve has been +0.3 runs above average. All three of those pitches were clearly in the negative for most of the season. (I haven’t mentioned the curve but it’s -5.3 on the year)
So is this a real thing? Well, Wacha deciding to throw more changeups and less cutters is definitely real and in two starts, it’s been a success. Whether that can continue, who knows? But it’s something and I want to believe Wacha can have a strong end to what is probably the end of his Cardinals career.