Let’s Put Tarik Skubal Back on the Tigers

The Detroit Tigers are one of the hottest teams in baseball. Since the calendar flipped to August, they’ve gone 7-3, scoring more than six runs per game in the process. In a muddled American League, that puts them right in the thick of the AL Central and Wild Card races. That, in turn, means they’re back in the hunt for a World Series ring. This burst of activity has them about as likely to make the playoffs (and win a ring) as they’ve been in the last few months, in fact; they’re back above 30% to reach October after dropping as low as 18% the day they traded Tarik Skubal.

That feels weird! Less than two weeks ago, the Tigers traded their best player, perhaps the best pitcher in baseball, for three prospects. They followed that up by trading Casey Mize, who had briefly inherited the title of top Tigers pitcher. It was a classic deadline sale – not a thread-the-needle plan with some additions and some subtractions, but a declaration that the plan was to get ‘em next year, and the years after that.

Does this mean the Tigers shouldn’t have traded Skubal and Mize? I’m not here to opine on that (OK, fine I’ll opine at the end of the article, but you have to read it first). But they did make those trades, and they did go on that hot streak, so here we are. The Tigers can’t un-trade those guys. MLB doesn’t have a takebacks rule. But I can’t help but wonder how the Tigers would look if they hadn’t made any moves at the deadline, and so I decided to write about it.

The key to answering this question is to build a tool that can take hypothetical rosters (the Tigers with their two top pitchers back) and plug them into today’s actual standings and schedules. Luckily, I have one of those. I told my computer to undo the Skubal and Mize trades while leaving the rest of the deals from the deadline intact. Obviously that’s not a perfect assumption – the Dodgers probably would have landed on a separate starter if they didn’t get Skubal – but it does a good enough job for my purposes, which is to analyze how different Detroit’s path in particular would look if the team had held its course at the deadline instead of pivoting to the future.

The Tigers have backfilled their rotation thanks to some spot starts by Drew Anderson and Jackson Jobe’s return from injury. That’s meaningfully better than nothing; it’s surely part of why the Tigers made the trade in the first place. Even with two remaining starters (Jack Flaherty and Justin Verlander) on the shelf, they still have a functioning rotation. Here’s what it looks like today, with each pitcher’s rest-of-season Depth Charts projections:

Our system has that as the 19th-best rotation in baseball, though my own outlook is slightly rosier; I think that Melton and Jobe are better than their projections imply. The Tigers are in a position to compete for a playoff spot thanks to their pitching, undoubtedly so, but that’s largely because Skubal and Mize each made 16 starts and each notched ERAs around 2.75. After that, it’s been Melton and Montero picking up the slack that Valdez, Flaherty, and Verlander have left; Skubal and Mize recorded nearly as much WAR as the rest of the rotation combined before they departed.

The Detroit bullpen has been poor so far this year. How poor? Well, we give Tigers relievers credit for 1.4 WAR. Half of that comes from Anderson and Montero’s relief work, though; Montero flexed to the ‘pen when everyone was healthy, and Anderson has spent most of this year as a short-stint reliever. With those two now assuming starting responsibilities, we think the group that’s left is abysmal, a bottom-five unit. Put all of that together, and it’s no wonder that we project Detroit to allow 4.62 runs per game the rest of the way, far more than it has surrendered so far.

OK, then: Let’s bring back the two aces and shift some arms into the bullpen. I swapped in Skubal and Mize for Anderson and Jobe, then bumped those two up to priority bullpen arms to give the relief corps some extra oomph. The new rotation (same as the old, pre-trade rotation) naturally looks a lot better:

The real question, though, is what that does to their Playoff Odds. We consider the true talent of the Tigers as currently constituted to be slightly worse than a .500 team. With their two best pitchers back in the fold, that true-talent winning percentage goes up 27 points, from .497 to .524. And while that doesn’t sound like a huge move, the Tigers are in the perfect position for that boost in talent to matter most. The AL Central is ripe for the taking. The top four teams are within four games of each other, and while the three clubs that Detroit is competing with all made deadline moves, none was earth-shattering.

It’s not just about a division title, either. Winning the Central comes with a decent chance of a first-round bye, because the AL West has been even worse this year. With the three best records in the American League all residing in the East, whichever team finishes best out of the other divisions is going to get a relatively easy draw considering its final record. That means that adding expected wins is about as valuable as it could get for any of the teams on the AL Central and AL West bubble; more wins doesn’t only make you more likely to win your division or the last Wild Card slot, it makes it more likely that a division title will come with a bye.

Reverting to the old rotation would make the Tigers narrow favorites to earn that bye. That’s a really big deal; winning three playoff series is a lot easier than winning four. It more or less doubles your odds of winning the World Series, because it removes a 50% chance of losing before the tournament really gets going. My model sees it this way, with or without Skubal and Mize:

Like I said, that’s a big bump. Adding two percentage points to your odds of winning the World Series is no joke. Even when we projected the Tigers as clear division favorites before the season, we only gave them a 4% shot at winning it all. Why can adding just two players increase their odds by so much? It’s because they’re in the perfect spot for those wins to apply with leverage; most teams don’t hit August in a position where one win could make the difference between staying home or playing in October, or between a bye and a Wild Card round berth.

I promised that I’d answer whether the Tigers “should” have traded Skubal and Mize, and I came up with a rough framework for that assessment. I took the same tool I’m using to build hypothetical alternate lineups, rewound it to the start of the season, then figured out how much adding a win’s worth of projections at various projected records would affect World Series odds. Here’s a rough distribution of how much an extra win matters, from various starting points:

Next, I got even more theoretical. I took some distributional studies that got left on the cutting room floor when I updated prospect valuations and worked out, more or less, the odds that prospects of the caliber traded for Skubal and Mize would turn into average regulars or better, plus the average WAR per year delivered in those outcomes. I also looked at the last six years of Tigers teams to figure out how many extra wins adding players like that to replace weak links would be worth (limiting those weak links to the rotation and the outfield, to match the prospects). I worked out that the guys traded to the Tigers project to boost their average projected wins by around 1.2 per year.

At this point, I’ll stop and point out that I’m doing a lot of approximating, so the error bars are large here. But with that caveat, we can do the math. Say that the Tigers bounce around between 78 and 90 projected wins for the next six years, and take the average of those World Series-odds-per-win sensitivities. Multiply that by the 1.2 wins per year I think the extra prospects are “worth.” Multiply that by six years of team control. You get an added 3.3 percentage points of World Series odds, comfortably more than the boost they’d receive from having Skubal and Mize the rest of the way this year. That might understate it, too. If the Tigers didn’t sell, they likely would have bought, but probably only on the margin, considering where they were in the standings and their underperformance over the first four months of the season. The risk of going all-in would have been too high. While we don’t know the counterfactual there, it’s reasonable to think that it would’ve made their future teams even a little worse, for small present benefit, amplifying the effect I’ve already measured here.

That’s an unsatisfying answer for me, but that doesn’t make it less true. The Tigers stand to benefit a lot from raising their floor in future years. Even though they’re in a place of maximum leverage right now, making the playoffs is not the same as winning the World Series, and even with Skubal, Mize, and a few marginal upgrades, this year’s squad would’ve faced a huge uphill battle, likely underdogs in nearly every round of the playoffs (against various AL East squads and then the Dodgers NL champions). Getting a little better in many future years doesn’t sound as fun as being a lot better right now, but my math suggests that it’s pretty clearly the right move, even taking into account their recent performance.

I doubt the Tigers made this exact calculation when they opted to deal their two best pitchers. But I assume their motivation was at least similar in spirit. I’m all for trying to compete, and I generally dislike teams perpetually playing for the future. But this was an extreme case. The Tigers haven’t been amazing this year, Skubal and Mize were rentals, and they fetched enough return that it looks likely to change the trajectory of future teams enough to matter, given how many weak roster spots they’ve tended to carry and the competitive window they’re in. Not the most exciting conclusion, perhaps, but hopefully a salve to observers who, like me, saw the Tigers start winning and thought, “Boy, Skubal would make this team look better, huh?” They may yet go on a run. Heck, they might win it all anyway, despite making these deals. But even taking into account their winnable division, and even cheating a little and taking into account how well they’ve played after the deadline, I think they made the right decision by the numbers.