I'm not a super big fan of K/9, which answers the question, what are the chances a given out is achieved via strikeout. Instead, I'd rather know the chances that a given plate appearance will result in a K. That's K%. And in the case of Littell, that number went up even more between 2018 and 2019, namely from 13.9% to 21.9%. K/9 understates the improvement, since it can be high even if the pitcher is giving up tons of hits. An improvement in K% means there's simply that many fewer opportunities for damage. His BB% also improved year-over-year. That said, it's still not an elite level of strikeouts. The AL had dozens of guys in the 30s. The league average was 22.7%. He's young and may improve but I'm not really banking on him.