This story was excerpted from John Denton’s Cardinals Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

SEATTLE -- Dating back to the offseason, I’ve quietly had this theory about the 2023 Cardinals -- as currently constructed -- and their hopes of making their first deep playoff run since 2019.

It goes something like this: If Jack Flaherty can somehow again become the Cardinals’ ace, and he can shed the injuries and drama of the past of the few seasons and rediscover the electric, you-can’t-touch-this stuff, St. Louis can contend with powerhouses such as the Braves, Phillies, Padres and Dodgers for supremacy in the rugged National League.

However, if Flaherty can’t rediscover what he had in 2019 (231 strikeouts over 196 1/3 innings) or early 2021 (when he got off to a Cy-like 8-1 start) and he’s simply the team’s third- or fourth-best starter, a Cards franchise that hasn’t won a playoff series in three seasons is likely headed for another early October exit.

On Sunday in Seattle, Flaherty reminded the Cardinals just how valuable a true ace can be for a club with World Series aspirations. With the team on the verge of being swept by the Mariners for the first time in franchise history, Flaherty was the stopper it desperately needed. Over six innings, he allowed just five hits and three earned runs while striking out nine, as the Cardinals rolled to a 7-3 victory.

“He competed extremely well,” said Cards manager Oliver Marmol. “Before the game, we talked about him as being a guy that understands what’s at stake and putting an end to [a losing streak]. He embraced that challenge and did exactly that.”

What Flaherty did on Sunday was pitch like the dominant arm the Cardinals need to send fear through opposing lineups. What made the performance even more impressive was that Flaherty had to wade through some struggles, ignore some chirping from Seattle superstar Julio Rodríguez and even stare down emotions he sometimes let get the best of him.

The 6-foot-4 right-hander was dialed in from the start, throwing a sharp slider (42 inches of vertical break) and a knuckle curve (59 inches of vertical break) to strike out Rodríguez to open the first inning. Flaherty encountered trouble an inning later and was hit hard, but he found another gear and used a 94.9 mph four-seamer to escape more damage. When he left the mound, Flaherty angrily pointed fingers at baserunners, umpires or, well, anyone in his line of sight. 

“Sometimes you’re just fired up or trying to find ways to get fired up, because you create things or create little games,” said Flaherty, refusing to specify the target of his ire. “Sometimes you just make stuff up [for motivation] and you run with it.”

Getting Flaherty riled up proved to be foolish for the Mariners. He retired 11 of the next 12 hitters, and the one who reached, old friend Kolten Wong, was erased in a double play. His final two strikeouts came on 96.8 and 91.4 mph four-seamers.

More ace-like stats from Flaherty: He’s now induced an MLB-best eight double plays. Also, Flaherty has incredibly allowed six or fewer hits in 30 straight starts, a streak that dates to September 2020. It is MLB’s longest active streak of outings with six hits or fewer allowed and the longest run ever by a Cardinals pitcher.

“Flaherty is a guy, if you think of his preparation, it’s hard to beat it,” Marmol mused. “This is a guy who shows up every day. The days in between his starts are pretty incredible, and he doesn’t take anything for granted. When you do that over time, that’s what gives you consistency. Certain guys are good and rely on their talent, and other guys develop their talent. Jack is a guy who develops his talent, and he’s never going to give in.”

Never give in, you know, like an ace never would do. For St. Louis to be the team it wants to be this season, it needs Flaherty to be the ace he closely resembled in a critical win.