The Cardinals fired longtime manager Mike Matheny one game before the All-Star break this year, with the team at 47-46 for the season. The organization promoted Mike Shildt to replace Matheny, and the club has gone [27-12] with Shildt in charge, winning their last nine series matchups, including six against teams with winning records. This is how the Cardinals’ playoff odds have changed during Shildt’s brief tenure as manager.

Things didn’t improve immediately. After a collection of games against the Cubs, Reds, and Rockies, St. Louis’s chances of reaching the postseason had actually deteriorated a bit by the end of July. As they entered August, the Cardinals had just a 7% probability of qualifying for the playoffs.

With a 20-6 record in August, however, Cardinals’ odds have improved almost tenfold. Coinciding with that improvement in the standings, the Cardinals took the interim tag off Shildt’s title and extended his contract through 2020. Some considered the timing a bit odd.

Here’s Ken Rosenthal:

#STLCards clearly different and better under Shildt, but team still could have waited until season’s end before awarding him the three-year extension first reported by @dgoold and @BNightengale. We’re talking about a 38-game sample; Shildt has yet to experience real adversity. — Ken Rosenthal (@Ken_Rosenthal) August 28, 2018

Joe Sheehan cast doubt that any interim manager would be best candidate:

I've said it before, I'll say it again: What are the chances the best guy for a job just happened to be the guy sitting next to the guy you fired? In what other business would you make personnel decisions this way? — Joe Sheehan (@joe_sheehan) August 28, 2018

Mike Petriello wonders how much of the Cardinals’ good play is actually related to Shildt’s managing.

Mike Shildt seems like he's done a great job. Now, how much of STL's comeback is due to: 1) Carpenter losing his mind

2) Completely turning over OF

3) Largely turning over BP

4) Not having Matheny

5) Shildt? ? Hard to say. Seems like you didn't *have* to make this move now. — Mike Petriello (@mike_petriello) August 28, 2018

These comments were all authored by smart, impartial observers — observers who, in each case, question the wisdom (or, at least, the timing) of Shildt’s extension. While all raise legitimate points, there’s probably reason to believe that Shildt isn’t the typical interim replacement.

First, a note on the timing. While the club wasn’t bound to extend Shildt, it also seems likely that they’ve been preparing for this move for some time. Even though the Cardinals showed considerable loyalty to Matheny, the writing had been on the wall for some time regarding his future in St. Louis: Matheny himself knew that, if the season went poorly, he would likely be dismissed. When I first discussed Shildt after Matheny’s firing, I said the following:

Mike Shildt was essentially handpicked by John Mozeliak for his current role. Mozeliak, now serving as the president of baseball operations, hired Shildt back in 2003 when the former was still serving under GM Walt Jocketty. Shildt worked as a coach in the minors for five years before managing short-season Johnson City. He helmed the summer club annually for three years before earning promotions to Double-A Springfield and Triple-A Memphis before eventually earning a post as an MLB coach before the 2017 season. When Mozeliak fired his first shot across Matheny’s bow by removing Chris Maloney as third base coach midway through last year, Shildt took on that role. Shildt has more seasons managing professionally for the Cardinals than the departed Matheny possesses.

Shildt’s deliberate path toward the managerial position — and longtime coach Jose Oquendo’s clear interest in working alongside him — both indicate that the decision by the front office is based less on what the Cardinals have done since Shildt was appointed to the interim role and more on their evaluation of Shildt’s credentials for the job. Indeed, the Cardinals likely regarded the recent success of the team as a convenient pretense upon which to announce a decision they had likely already made, as opposed to representing their reason for making it.

If we take for granted that Shildt’s appointment was a forgone conclusion, the timing of the club’s announcement makes sense. Consider: if the Cardinals were to make the playoffs and then extend Shildt, no one would bat an eye. But if things were to go south for the team over the next 30 games and the club extended Shildt anyway, the move would look worse than if the decision had already been made. It’s possible that the organization had every intention of naming Shildt their full-time manager as soon as they fired Matheny, but thought it better to get some handle on how he would deal with the clubhouse and in-game decisions. Any fears were assuaged early on, though, and a win-streak provides convenient cover for removing the interim tag.

There’s still the question of how much effect Shildt has actually had on the team. Instilling confidence, having team meetings, winning, and communicating well are good talking points, but they are also the same points upon which many of Matheny’s supporters relied when defending the now-deposed manager. It would be nice to point to some more concrete changes without having to rely on soft skills and the won-loss column. If the Cardinals are just on a random good run with Matt Carpenter playing like an MVP and getting some batted-ball luck on the pitching side, it would be hard to say exactly what Shildt is doing differently.

Here are the Cardinals position-player numbers from the first half and the second half.

The Cardinals’ Turnaround Half G BB% K% AVG OBP SLG wRC+ Def/162 BsR/162 WAR/162 1st 94 8.4 % 22.7 % .244 .315 .399 94 51.9 7.9 21.0 2nd 39 8.6 % 19.3 % .265 .339 .444 111 66.9 19.9 37.8

Matt Carpenter is definitely responsible for a good portion of the observed improvement. It’s also promising, however, that non-first basemen have recorded a 103 wRC+ for the Cardinals in the second half. Half of the change in batting average and on-base percentage can be tied to simply putting more balls in play. The Cardinals did change hitting coaches, bringing in George Budaska, who has a good relationship with Kolten Wong, among others. And while tying the installation of a new hitting coach to the reduction in strikeout numbers might be a stretch, one also finds that, of the three players who lowered their strikeout rates by at least five percentage points from the first half to the second half, two saw more steady playing time (Jedd Gyorko, Kolten Wong) and a third was told by the new hitting coach that he wasn’t using both eyes to look at the ball.

The other noticeable changes above occurred in baserunning and defense. Matheny had long been criticized for poor baserunning and for preferring offensive over defensive skill when deciding playing time. The Cardinals have miraculously gone from a team that was awful stealing bases in the first half — one with 33 steals in 55 tries — to one that is stealing more often with a better success rate (20 steals in 26 attempts).

As for the defense, Shildt moved Carpenter from third base to first base, made Jedd Gyorko the full-time starter at third base, and put Kolten Wong out there every day instead of just two-thirds of the time. If we assume Carpenter is five runs better than Jose Martinez at first base, that Gyorko is about 10 runs better than Carpenter at third base, and that Kolten Wong is about 10 runs better than Gyorko at second base (call it three runs when adjusting for playing time), those moves alone account for nearly two wins over the course of a full season. Emphasizing defense essentially created an extra average player, and giving some of Jose Martinez’s playing time to Gyorko only crawls back about one-third of the defensive gain.

On the pitching side, the Cardinals have gotten luckier in the second half, particularly with the bullpen as the 4.32 FIP is worse than the first half’s 3.97 even though the ERA has gone from 4.48 to 3.55. Meanwhile, they’ve gone from one of the worst bullpens in baseball by WPA to the top 10 in the second half. Some of that luck is actually the defense, which we just discussed. Another part is usage. The graph below shows the first half FIP and leverage index for Cardinals relievers with at least 10 innings.

If things are going well, as many dots as possible will appear in the top left (high leverage, good performance) and bottom right (low leverage, poor performance) with as few dots as possible in the bottom left (low leverage, good performance) and top right (high leverage, poor performance). As the graph above shows, the club has endured a lot of poor performances from highly leveraged relievers. Some of this might be bad luck. It’s also possible, however that Matheny had difficulty differentiating between either (a) important moments and unimportant ones or (b) good relievers from bad relievers or (c) both. His reliance on proven veterans instead of present-day talent meant pitchers were utilized poorly. Ultimately, it might have been his advocacy for and extreme misuse of Greg Holland that cost Matheny his job. Here’s what the Cardinals’ bullpen usage and leverage index looks like under Mike Shildt.

Only lefty waiver pickup Tyler Webb, down there in the lower left corner, looks really out of place. Carlos Martinez has made just three appearances and doesn’t appear on the graph, but his gmLI is 1.4 which would also place him in the favorable upper left corner. Shildt identified Jordan Hicks, Dakota Hudson, and Bud Norris as his best relievers and has maximized their usage in important situations. It wasn’t just the composition of the bullpen that changed with the manager, it was the willingness of that manager to use his best relievers in important moments. Add in a defense, and some deficiencies in the overall numbers can be hidden.

Quantifying manager impact is a difficult task, one that’s opens to criticisms. Ultimately, players win the games on the field. Providing more playing time for Kolten Wong and Jedd Gyorko, though — along with improved coaching for Marcell Ozuna — might have had an effect on offensive numbers. Making the infield defense significantly better, meanwhile, has likely helped a pitching staff that didn’t actually perform any better by fielding independent metrics. That task gets tougher with Kolten Wong and Jedd Gyorko on the disabled list. It’s hard to know whether the changes to bullpen usage will lead to sustained success, but they’ve definitely made a difference thus far. It’s fair to question the timing of the permanent hire and impact on wins and losses, but there are some pretty concrete changes behind the Cardinals’ turnaround and some real logic behind team’s long-term faith in Mike Shildt.