Baseball fans’ brains are littered with obscure names and trivia. We all know names like Wally Pipp, Fred Merkle, and Johnny Vander Meer for their rather absurd places in baseball history. Five of those baseball names that may or may not be stuck in your brain for trivial reasons are: Freddy Garcia, Jamie Moyer, Gil Meche, Joel Pineiro, and Ryan Franklin. If that quintet is meaningful to you, it’s because every single game of the 2003 Mariners season was started by one of those pitchers.

In the modern era of five-man rotations, that team was the only one ever to get through an entire season without once turning to a sixth starter. It’s a trivial feat, but one that I find myself wondering year after year whether it will ever be repeated. Now that we’re halfway through the 2016 season, it’s time to assess the situation and determine whether or not this will be year of the second immaculate five-man rotation.

One-in-five teams have already used 10 or more starters this season and only two teams are left standing in my personal race to a perfect five-starter season: the Cubs and the Cardinals. Can either team match the 2003 Mariners?

The two remaining starting fives comprise familiar and talented pitchers: Jake Arrieta, Jon Lester, John Lackey, Jason Hammel and Kyle Hendricks for the Cubs and Adam Wainwright, Michael Wacha, Mike Leake, Jaime Garcia, and Carlos Martinez for the Cardinals. The range of talents across that collection of 10 pitchers is wide, naturally, but it’s also worth noting that there aren’t any true duds in either of these rotations. Even the weakest member of each would start in almost any of the other 28 rotations across the league.

But these two rotations aren’t created equal. There can be no question that, on paper, the Cubs have the more talented rotation. Their starting rotation has combined for a microscopic 2.85 ERA which, unsurprisingly, leads the majors. The Cardinals rotation sports a decidedly less superhuman 3.99 ERA, although that’s still good enough to rank ninth in the majors. Just one member of the Cubs’ group has a strikeout rate below 20% (Hammel, 19.5%), while the strikeout leader in the Cardinals’ group only reaches 20% by rounding up (Wacha, 19.95%). If forced to choose between these two rotations, it would be extraordinarily challenging to mount a convincing argument in favor of the group from St. Louis.

The talent discrepancy should make the Cubs the favorite of the two teams to pull of this quirky achievement, right? If only. This is an achievement that’s as much attributable to luck and random variance as anything. Pitcher health is obviously one of the key thoroughly unpredictable components at play here, but another one is equally unpredictable: weather. The Cubs’ chances at riding just five starting pitchers through an entire 162-game season likely ended months ago when rain postponed their April 27th game against the Brewers. That game has since been rescheduled as a doubleheader to take place on August 16th. That doubleheader will give the Cubs 10 games in nine days and, as a result, will require a sixth starter. This is the same situation which sunk the 2012 Reds’ run at a five-starter season. Their rotation – Bronson Arroyo, Homer Bailey, Johnny Cueto, Mat Latos, and Mike Leake (again!) – started 161 games that year but a mid-August doubleheader forced them to use spot starter Todd Redmond for one game.

And so we turn our sights to the Cardinals. Their schedule is clear of pesky doubleheaders, at least for now, but do they have the right collection of talent to make it happen?

The first question is whether or not the rotation has the health to make this feasible and the answer isn’t terribly promising. Adam Wainwright will turn 35 years old later this summer, is having the worst statistical season of his career and is now more than five years (and nearly 800 major-league innings) removed from his first Tommy John Surgery. Jaime Garcia hasn’t been able to stay on the mound for more than 30 starts in one season since 2011. Then there’s Carlos Martinez, who was shut down at the end of last season with a shoulder injury that lingered into this year’s spring training. It’s easy to imagine an injury derailing any of their seasons, but let’s play for a moment in that beautiful, ideal world where these five pitchers remain healthy. In that world, will the Cardinals stick with this group for the remainder of the season?

The Cardinals’ motivation this season is to win. Although they currently have the third-best run differential in the National League, they sit two games out of a Wild Card position and just a game and a half ahead of their division rival, the Pirates. It seems unlikely that the Cardinals are going to run away with a playoff position and, as a result, they’ll want their best five pitchers on the mound night in and night out and, unfortunately, their options behind their current five are exceedingly limited. Lance Lynn and Marco Gonzales are both lost for the season to Tommy John Surgery and Tim Cooney has been sidelined all season with a shoulder injury. As a result, the Triple-A depth from which they can draw rotation replacements includes guys like Jeremy Hefner and Jerome Williams who represent a massive step down in talent.

The one notable exception is their top prospect, Alex Reyes, who has made eight starts in Triple-A since the end of his 50-game suspension for a positive marijuana test. Reyes is just 21 years old and striking out nearly a third of the batters he’s faced so far this year. Unfortunately, he’s also walking more than one in 10 batters and has yielded 21 runs (19 earned) in his 34.2 innings of work. If St. Louis reaches the point at which Reyes represents their best option, a bullpen assignment could be likely, because who is he going to replace? Leake may be the club’s weakest rotation piece at the moment, but he’s in the first year of a five-year, $80 million contract. Demoting him to the bullpen seems unlikely, at best. They could send Jaime Garcia to the bullpen as a means of managing innings for the oft-injured pitcher, but with the way Garcia performs when healthy, that wouldn’t be an easy move to make. It appears likely that the Cardinals are currently looking at their best rotation for winning in 2016.

This isn’t a team that seems like it will need need a rotation upgrade this season and that might just make this Cardinals team the perfect candidate to do a 2003 Mariners impression. Their pitching depth has been decimated by injuries and, given that they intend to make a run at the postseason, they stand to benefit from sticking with their solid, if somewhat unspectacular, rotation. If they stay healthy, that is.