Cubs lefty pitcher Daniel Norris, a second-round pick in the 2011 MLB Draft, made his Cactus League debut with Chicago on Sunday, eight days after he signed a one-year, major league deal with the team. That debut featured two scoreless innings in relief of Kyle Hendricks, a role that’ll become even more familiar to him as the season goes on.

He will presumably pitch as a reliever with potential to start in a swing-role. If he ultimately succeeds as a reliever and starter, the likely reason will be his changeup.

After reading this post, your biggest takeaway should be Norris’ league-best changeup spin axis. Norris’ changeup spins at 8:45 o’clock (figure below).

Also unique is the way Norris’ changeup drops vertically. His offspeed pitch generates 23 percent more vertical drop than league average in part due to its top-two percentile seam shifted wake. As we’ve noted here on CHGO, the Cubs love seam shifted wake.

Let’s take a look at this heavy breaking changeup. You can see him pinpoint the pitch perfectly to St. Louis’ Paul DeJong, who whiffs ahead of the pitch.

However, pinpointing changeups was a problem for Norris last season. While his changeup had an xwOBA of .253, the pitch nevertheless gave up more runs than prevented runs (+6). Why?

As shown in the figure below, the further Norris throws his changeup inside to righties, the greater the probability for runs. And vice versa, if Norris keeps his changeup away from righties (as he did to DeJong above), the greater the probability for outs.

Yet if you look at Norris’ changeup location to righties below, you will see some leakiness down-and-in. This overlaps high run value in the figure above — here, we have a possible intervention target for pitching coach Tommy Hottovy. Why is the changeup leaking down-and-in? Is that intentional? If that’s not intentional, why not throw changeups there less often? These are all questions that might be asked.

If Norris does improve his command, the probability he becomes better than league average in value appears high. Of course, that is a big “if.” But Hottovy and the pitching infrastructure love “ifs.”