Marlins Run Differential: Important Facts and Fallacies

The 2021 Major League Baseball season is in the midst of its second month. Still, this year"s campaign is already beyond interesting and intriguing with some clubs holding unexpectedly positive records, and vice versa, however, the small sample that is still attached to any kind of stat, let alone a team"s record, could turn some current assessments into deceptive claims, which could be the difference between a right and wrong prediction. That being said, the 18-22 Miami Marlins are one of the most interesting squads in the league. On the one hand, the team is in its most favorable early position in recent memory. On the other hand, the case of the Marlins run differential has seen some experts puzzling.

While Miami ranks fourth within the NL East division, they are the only remaining team on NL"s East coast with a positive run differential. According to Baseball-Reference, the Marlins score an average of about four runs per game. At the same time, they allow 3.8 runs per game, making for an official run differential of 0.1. The closest team in the NL East, the New York Mets, are at -0.2. Furthermore, the Marlins run differential is tied with the Cubs for the 13th-best in all of Major League Baseball.

So, what is the deal with this statistic? Here is the real meaning behind this curious case, as opposed to what you may hear in the media environment.

2021 Marlins Run Differential: The Deal with Miami"s RD

As already laid out, the Marlins are the only team in the NL East with a positive run differential after seven weeks of MLB baseball. The Marlins run differential of 0.1 is the 13th-best in the whole league as well as tied for sixth-best within the National League. There are many different thoughts and opinions regarding the combination of that and their record, which is four games under .500. Yet, it is hard if not impossible to give more credibility to run differential than a win-loss record, the true means of success measurement. Nonetheless, there are some valuable takeaways from the limited importance these numbers carry at this stage of the campaign.

Fallacies: The general portion of the fandom and most experts in sports media alike might have attributed the Marlins run differential and the concurring phenomenon to a few factors. Values such as lack of character, lack of clutch hitting, etc. may have dominated the discussions. Furthermore, they could have also made for some brutal improper breakdowns of both the team"s path going forward and individual players" capabilities.

The truth is that the balance within the units of the Marlins" roster is similar if not the same as last summer. That is despite the contrast the aforementioned groups may have tried to establish with the 2020 Marlins team that snatched its first postseason berth in 17 years.

Facts: Upon further review, the way a +5 run differential accompanies Miami"s eighteen wins this season is neither odd nor surprising. This is because the difference between the Marlins" actual record and their Pythagorean W/L projections isn"t all that big. Miami"s 158 scored and 153 surrendered runs would make for an estimated record of 21-19 after the team"s first forty-game slate.

There are some fascinating notes to focus on here. Firstly, the obvious difference is that the real record is losing and the projection resembles a winning stint. Moreover, this three-game downturn is a bigger step away from the Pythagorean estimates than any other MLB club so far, except the Minnesota Twins. That is whether the topic is a positive or negative difference.

These three games however are still too slim of a difference to be one of any significance. In both cases, the Marlins" record retains its near-.500 character, likely also wandering near the fourth or third place in their division. Therefore, even if the difference is too big when compared to all the other teams in the MLB, that would mean the team has not played enough games yet for there to be any difference between the two situations.

The last sentence makes for a smooth transition to a less detailed yet even more important underlying reality behind this so-called “paradox". It states that the sample size of that 18-22 record, or even if it was 21-19, is simply too small for any record to be conclusive at this point of the 2021 campaign. Whether teams finish with the best or the worst record in any given year, they will experience both strong and weak streaks.

If the end-of-year record is expressed as an “overall identifying performance" or “an average measurement for the performance over the whole year", the so-called “rule of averages" would mean that the shorter stints a team goes through would, most often, be anything but the winning percentage they end up with at the end of the year. The same pattern can be traced in individual or team stats in all sports, and probably in most averages in the world of statistics. In other words, it is too early for any extreme value to have any meaning. Furthermore, the case with slight paradoxes such as the Marlins run differential is no different.

2021 Marlins Run Differential: A Deep Dive Into the Units

Now that we"ve concluded that the “paradox" of a positive Marlins run differential and a losing record is either not that far from reality or irrelevant due to the small sample, it is time to dive deeper into the units of the roster and what their potential improvement/downfall would mean for the Marlins" record.

Lineup: The Marlins currently rank 23rd in the league with 158 runs scored. Despite that no-so-impressive position for Miami offensively, the end-of-season projection gets even grimmer.

Miami"s three best hitters this year, Miguel Rojas, Corey Dickerson, and Jesus Aguilar, all average figures significantly above their recent applicable track record. For instance, through 150 plate appearances, Rojas has an on-base percentage of .367. At first sight, this comes in as an impressive number, dramatically besting the MLB average of .313.

However, excluding the shortened 2020 campaign, over his last two seasons, both seeing him play more than 130 games, his OBP drops to .314. This is disappointing even when compared to this year"s league-wide figure, let alone those of the previous few campaigns. More importantly, as the season progresses, his sample will increase and the .364 figure will begin to balance out and near its previous values. All of that estimates a brutal downfall for Miami"s starting shortstop.

The same trend can be observed with Aguilar (.366 – .339 between 2017-2019) and Dickerson (.359 – .320 between 2016-2019). Even if two of those three wider-sample figures remain above MLB"s 2021 average, they resemble a big decrease from their current numbers. Therefore, this will result in a weakened lineup that could fall further from the 23rd place they hold within the league.

On the contrary, Brian Anderson and Garrett Cooper promise to post noticeable increases between now and the end of the season. Anderson"s .255 OBP is very low as opposed to his .350 between 2018 and 2019. His workload in that span was 1,190 plate appearances over 282 games. Moreover, Cooper had an OBP of .344 in his only campaign with over 400 AB whilst his current figure is just .283.

Both Anderson and Cooper should significantly improve going forward. However, the downfall of other players, as well as the risk rookies such as Jazz Chisholm carry, should make the downside heavier than the upside. All in all, the best-case scenario is for the lineup to uphold its 23rd position but it can be anticipated to fall even further.

Starting Rotation: As always, Miami"s starting pitching staff is beyond adequate and the only saving grace of a thoroughly underwhelming ballclub. With an ERA of 3.76, the unit is the tenth-best in Major League Baseball. Between that and the sensational performance displayed by the bullpen, the Marlins have the sixth-lowest team ERA in the majors.

As regards the rotation specifically, though, the top part is playing close to their previous turnout. Firstly, Sandy Alcantara‘s strikeout rate is 9.0 K/9, compared to 6.9 during his only full year, 2019. Alcantara started 32 games on the mound for Miami that season. This might seem like a notable step away from the wider-sample evidence and could decrease down the road. However, this isn"t the case with his control and big-ball capabilities.

When it comes to walks, the Dominican native conceded 2.8 bases on balls per nine innings. This is much lower than his 3.7 in 2019. However, what could be an indicator that this value could remain in that range is that Alcantara has at least six starts in each of his past four campaigns, and every year that figure drops. His number in the BB/9 department fell from 6.1 in 2018 (6 starts) to 3.2 in 2020 (7 starts). While the seasons with fewer starts lack credibility and prove nothing, it could show a favorable tendency that could keep Alcantara"s control in positive territory. Furthermore, he averages 1.1 home runs per nine, a figure which hasn"t been south of 0.9 and north of 1.0 since 2017.

Pablo Lopez, the group"s No.2 starter, is in the same boat. Lopez started no fewer than ten games in each of his first three campaigns on the major-league level. His 8.4 K/9, 2.9 BB/9, and 0.7 HR/9 are all close to his average numbers in that three-year stint, which remained as steady in a 21-start season as in a 10-start season. Even when compared solely to his 2019 campaign, his strikeout rate should remain in that range and his control display should improve if anything.

In the bottom part of the rotation, the Marlins face both risk and injury woes. Firstly, Trevor Rogers has put on an incredible performance through seven weeks of MLB baseball. His 1.84 ERA is accompanied by 11.7 strikeouts per nine, 3.5 walks per nine, and 0.4 home runs per nine. This is his inaugural campaign in MLB so it is impossible to predict what his figures will look like at the end of the year. However, as it stands, only his bases on balls are at a critical amount.

Furthermore, an injury to Elieser Hernandez has forced the Marlins to use Daniel Castano and Nick Neidert to complete the unit. Heading into the 2021 MLB season, Castano had started just six games while Neidert had only three relief appearances on an MLB mound. Yet another risky investment of a rotation berth but, overall, the impressive Marlins rotation shows no signs of slowing down.

Bullpen: A major-league bullpen group has too many pieces to go through all of them one by one. However, there is one terrific piece of statistics that could be indicative of sustainability for that unit. Facts: The Marlins not only have the eighth-most innings pitched by their relievers but have a better ERA than every team with fewer IP but two – the Indians and the Yankees.

2021 Marlins Run Differential: What Follows Next

The evidence has been clear – the positive Marlins run differential/losing record case isn"t a paradox but predicted a record close to the team"s real turnout result-wise. Moreover, it analyses too short of a period for either their actual record or the Pythagorean record to matter with a 162-game campaign in the background. Instead, this article offers a more wide-sample answer to the question of how the Marlins" winning percentage might wind up come October 2nd.

While the two pitching groups have had a phenomenal year with the potential to sustain that success, the lineup could fall further from its seat of misery. Therefore, the Marlins" season will look much closer to 2019 than to the 2020 playoff campaign, however, a drastic improvement over that 2019 season, which saw the Marlins almost 50 games under .500, is bound, proving the Marlins" overall prosperity.

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