The Numbers Behind the Mystery of Michael Wacha

It was as recently as 2017 when the then 25-year-old Michael Wacha (according to BrooksBaseball) was bringing his four-seam fastball at almost 96 mph (95.64 was the actual average).  That has been his career high.  He was also throwing his cutter faster (91.25 mph) than at any other time in his career.

Both of those pitches took a slight step back last year, with the four-seamer registering at 94.33 and the cutter at 90.06.  At these levels, though, they were still effective enough to set up that money-pitch change.  Wacha was 8-2 with a 3.20 ERA in an injury-shortened season.

As the struggling Cardinals set themselves to face the Philadelphia Phillies, they will do so without a healthy Michael Wacha as part of their rotation for the first time since early in the 2013 season.

The entirety of the decline of Michael Wacha seems directly tied to a sudden and surprising loss of velocity.  For the first time in his career, his four-seam fastball is averaging below 93 mph (92.93) and the cutter has also dropped to 89.03.

The advantage this drop gives to hitters is especially profound on the first pitch of the at bat.  What Michael would like to do – and what he has always done – is to use his fastball and cutter to get ahead in the count, putting the batter in a position where he has to offer at the changeup.  But – especially this month (in which he bears a 6.64 ERA) – that strategy has become a liability as batters are jumping on Michael’s first pitch.

Across all of baseball, the first pitch is hit about 10% of the time.  In May, 21 of the 95 batters Wacha has faced have jumped on his first pitch – about twice the usual rate.  And they have done so with predictable results.  Again, across all of baseball (according to baseball reference) batters who hit that first pitch (or are hit by that first pitch) slashing .348/.359/.610.  Against Wacha the 21 first-pitch hitters have 9 hits (a .429 average) that includes 2 doubles and 2 home runs – the two home runs being the defining moments of Michael’s struggles.

Of the 9 first-pitch hits surrendered by Wacha this month, 4 have come off that diminished fast ball.  Those pitches have averaged just 91.45, and when they have been up – and all four of them were up at least a bit – they become not much more than batting practice pitches.  Both doubles and one of the home runs hit against Michael came off this limping fastball.  In fact, the home run he allowed was on the fastest of these pitches – although fastest in this context is still just 93.1 mph.

That pitch came in the third inning of the first game of the May 22 doubleheader against Kansas City.  Already ahead 4-0, KC had a couple runners on base and were looking for the knock-out blow.  At the plate Jorge Soler was looking for that fastball, which, even though it was many inches inside was manageable enough that he drove it down the line and over the wall in left.  Knock-out blow achieved.  That pitch was well inside, but it was up.

As problematic as the fastball has been, the cutter may have become even more of a liability.  As the gap between the four-seamer and the cutter condenses – and it is now just a difference of 3.9 mph – its ability to slow down opposing bats also diminishes.  Three other first-pitch hits came off the cutter.  But this is a pitch that Wacha throws on the first pitch about one third of the time he throws the fastball.

It was a cutter – up in the zone of course, but slightly in on his hands – that Chicago’s Taylor Davis jumped on for the grand-slam home run that tied the May 4 game in Chicago at five each in the fourth inning.

As much, perhaps, as any other moment, that swing may have turned the tide on the Cardinal season.

The message from these numbers is fairly clear.  When Michael can get ahead of hitters, he still has plenty of weapons to polish him off.  Even in this difficult month of May, batters who fall behind Wacha are hitting just .136 (3 for 22) with no extra-base hits.

The problem is getting there, as Wacha has been ahead of less than 26% of the batters he has faced this month.  The clear reason is that he no longer has enough fastball to be able to leave it upstairs early in the count.

Where did the fastball go?  Well, that is the part of the mystery that we don’t have an answer for just yet.  But there almost certainly is an answer out there somewhere.  Michael insists that there is no physical difficulty – and I tend to believe him.  Wacha has extensive experience with injuries and knows how counterproductive it is to pitch through them.

So that leaves mechanical.  And mechanical means that – at some point – an answer should be found.

The move to the bullpen is not at all intended to be temporary.  Although the twists and turns of the season may bring him back into the rotation, that is clearly not the intention.  The Cardinals have – in essence – moved on.  Prospect Genesis Cabrera will get the first look, and behind him are Austin Gomber and Alex Reyes as they heal from their various ouchies.  With Macha not expected to be back next year, the organization clearly feels it’s time to turn the page.

That, however, does not necessarily mean that Michael Wacha’s significance to this organization is over.  As the recent bullpen fissures suggest, this team could certainly find an important relief role for a veteran pitcher with a 96-mph fastball.

Provided, of course, that someone can find where that 96-mph fastball has disappeared to.

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