What in good heavens is going on with Wade Miley?

Until the last week of August, Wade Miley’s continued major league resurgence was proceeding smoothly. Through August 24, the southpaw posted a quality 3.13 ERA in 152 ¹⁄₃ innings as he became a key cog in the Astros’ rotation. The return on investment for a one-year, $4.5 million commitment for Houston was quite good. He did post a then season-worst .384 wOBA in August, but there didn’t seem to be much reason for concern.

Then the first two starts in September happened.

The presumed Game 4 starter in a potential ALDS for a contender was suddenly not a sure-fire thing. Tuesday night’s start against the A’s, in particular, was a rough scene to watch unfold. While he was basically BABIP’d into submission, it was striking to see how effectively Oakland was able to handle Miley’s most notable pitch, the cut fastball. For context, five of the seven hits surrendered by the left-hander occurred via a cut fastball.

Both Miley and manager A.J. Hinch praised the approach of the A’s hitters following Tuesday’s defeat. Unfortunately, the lefty’s issues appear to only be a continuation of his previous start against the Mariners on September 5. That appearance was another instance in where Miley failed to escape the first inning. He didn’t even record a single out before mercifully being pulled only six batters in. The cut fastball was the offering of Miley’s demise as three of Seattle’s five base hits also occurred via the pitch.

The obvious reaction to this development is to speculate whether Miley is injured, tipping his pitches, or a combination of the two. But the left-hander is reportedly healthy while also stating in his latest post game comments that he is trying to figure out if he is inadvertently tipping pitches. In terms of tipping pitches, it does remain a distinct possibility, however, I am not trained to immediately pick up on the little things that may suggest so. I’ll leave that task to a more trained eye. But in terms of release points, there doesn’t appear to be much of a worthwhile difference, if any, between his starts before and on September 10.

There is little doubt that Miley’s cutter has become a liability in recent starts. However, it is arguably the single pitch that his entire arsenal relies on to be effective as he has thrown it 47.4 percent of the time this season. No other starting pitcher in baseball has a higher usage rate of the pitch than Miley. Out of the 453 outs he has recorded for the Astros, 47 percent, or 204 outs, have occurred when he throws a cutter. By wOBA, though, Miley’s cut fastball has progressively worsen since July.

Let’s take a look at what has specifically changed about the left-hander’s cutter. Specifically, pitch movement and break. Oh, look, there may be something.

The horizontal and vertical breaks of Miley’s cut fastball has noticeably altered compared to earlier this season. The Astros’ starter version of the pitch normally exhibits plenty of cutting action with a bit of sink, especially on to the hands of right-handed hitters. Below are two cutters thrown by Miley, one in April and the other in September, but look at where he is locating the two pitches.

The first cut fastball against Nick Hundley, who was with the A’s in early April, resulted in a strikeout. The second image in the GIF was against Tom Murphy during his start on September 5 and the result was a single down the third base line. As you can tell by the location of the pitch, Miley allowed his offering to Murphy to catch more of the strike zone while his cutter to Hundley was buried lower in the zone. While I am only showing two separate cutters from a large sample, it does partially validate what the horizontal and vertical breaks graphs are indicating.

In terms of pitch velocity and spin rate, everything looks reasonable. If anything, there has been an increase on both fronts, which isn’t something one would expect from Miley. There could be an argument here whether he needs to lay off the velocity and spin rate a tad as increases don’t necessarily guarantee better results.

If Miley’s cutter isn’t working like it should, then it lessens the effectiveness of his remaining pitch arsenal. For example, his changeup currently has an .836 wOBA this month, which he uses 20.4 percent of the time this season. His four-seam fastball (15.3 percent) has also been less reliable as its wOBA has gradually increased in August and September. Those two pitches, in addition to his cutter, represent roughly 83 percent of his total pitch distribution this year. If none of those pitches are performing, Miley is then in loads of trouble.

Could it also be a matter of simple regression? Let’s take a look at two seasons of Miley’s performance, which do tend to correlate well with one another outside of one or two noticeable categories: 2016 and 2019. Credit to Connor Kurcon of Six Man Rotation for his initial tweets on the matter earlier this summer.

Most of the categories above are similar enough, with the exception of ERA. In addition, there is also a noticeable difference between Miley’s respective BABIP for both seasons: .328 in 2016 compared to .280 in 2019. Of course, we’ve got to account the drastic overhaul to his pitch arsenal, but it is interesting to see numerous metrics line up similarly against different circumstances. That said, I think there is more to Miley’s issues than regression, although it is a probable factor to some degree in the matter.

Before September 5 against the Mariners, the left-hander was experiencing a streak of 42 starts of at least three innings pitched and less than four earned runs allowed dating back to 2018, as pointed out by mhatter106. That put him with some impressive company with names like Clayton Kershaw, Nolan Ryan, Jake Peavy, and Greg Maddux. These latest trends likely played a heavy hand in ending that streak. If Miley wants to start a new one, I’d imagine both he and the Astros would be perfectly fine with that development as the postseason looms large.