The Astros steamrolled the Oakland A’s over the weekend and the series sweep will rightfully receive the most attention, but there are a couple of noteworthy developments that need to be highlighted, as they could be indicative of future performances from atop the Astros rotation.

In this instance, it seems the co-aces of the Astros pitching staff, Lance McCullers Jr. and Zack Greinke, spent some time at White Castle during the winter. Judging by the details of their starts this past weekend, one spent more time there than the other. Regardless, the dividends for each could be considerable.

It needs to be noted that 4 games are but the first steps of the marathon that is 162 games, and to draw any conclusions would be premature. Having said that, the implications of these developments could be significant. Thus, an expedited examination is warranted.

LMJ has a lethal new weapon

From the get-go of McCullers’ Saturday start, it was apparent that his fastball control was off-kilter. Of the first eight sinkers he threw, only one found the strike zone. In his first inning of work, he quickly becomes in danger of walking the bases loaded with none out. Then, this happened.

McCullers would allow a run before getting out of the first, but it would be the only run that he’d surrender all afternoon, thanks in large part to his slider.

According to Statcast, McCullers’ new breaking ball averages a few ticks above his knuckle curve’s velocity and has slightly more horizontal movement as well. The big difference is in each pitch’s vertical drop, with a discrepancy of almost 20 inches.

Despite the impressive refinement of McCullers’ slider, it did not garner a ton of whiffs against A’s hitters. This is because they preferred to watch it get dotted up on the edges of the strike zone instead.

By the end of his 5-inning outing, McCullers had collected a remarkable 13 called strikes with his slider. Combined with the four whiffs it did net, the pitch’s Called Strike/Swinging Strike rate (CSW%) was a gaudy 50%.

Of McCullers’ 95 total pitches, he threw 34 sliders, which was more than any other pitch type.

While relatively new, McCullers’ slider had been featured in exhibition games last month. It’s logical to assume that he had fine-tuned it during the offseason, as evidenced by the superb command he displayed in Oakland.

Going forward, the slider looks to be one of McCullers’ primary pitches and could give him a fourth above-average or better offering. More importantly, if he continues to command it well, a decrease in walks could be a byproduct.

An old friend reborn?

Another Astros starter who ostensibly worked on their slider during the winter is Greinke. Prior to 2018, Greinke’s slider was his out-pitch for many years. In the past two, however, its primary use has been inducing weak or mediocre contact.

Those days could be over.

In Greinke’s Opening Day start against the A’s, he showcased a slider with substantially more vertical drop.

Though it was only thrown 12 times, Greinke’s slider averaged 8 more inches of vertical drop than it did in 2020, per Statcast. Granted, its average velocity was also down, which allows for more movement to transpire, but according to Statcast, compared to other sliders that have similar velocity, Greinke’s has both above-average vertical drop and horizontal movement. That was far from the case in 2020.

More will need to be seen before getting too excited, but a large sample size isn’t needed to accurately assess the legitimacy of pitch movement.

Greinke’s change-up is one of baseball’s best, so if he can again generate a proficient amount of whiffs with his slider, right-handed hitters probably won’t hit .305/.319/.527 against him like they did in 2020.