The early Miami Marlins, run differential, and preseason expectations

The Miami Marlins are 17-15 after the latest victory over the New York Mets last night. But Miami's strong play goes beyond their record; they have the fifth-best run differential in baseball and, when you look into deeper aspects of Miami's performance, you will find that the club leads the National League in Baseball Prospectus's third-order wins (a Wins Above Replacement calculation that accounts for strength of competition) and are tops in baseball in Baseball-Reference's Simple Rating System (a metric that combines actual run differential and strength of schedule).

The team looks very good when considering estimated run differential from component statistics as well. Just using the components of FanGraphs's Wins Above Replacement metric, Miami's offensive performance should have yielded 155 runs (two more than they have scored). When you combine the team's fielding accomplishments by UZR and their FIP runs allowed, the team has allowed 118 runs (10 fewer than they actually have allowed). According to this crude calculation, Miami's run differential should look more like a +35 run mark, which would make them a true-talent 0.623 win percentage team, the equivalent of a 100-win team.

Clearly Miami is not as good as their run differential currently shows, but usually when a team is performing well in terms of run differential and they have a mediocre record early, we tend to say that they are "underperforming" and due for an uptick in wins. However, that has not been the case for the Miami Marlins, since their expectations for the season began so low. Here's Kevin Ruprecht of Beyond the Box Score:

So, even with a very BABIP-driven offense and a pretty good top 3 in the rotation, the Marlins are only 16-15. What happens when the BABIP regresses? How far will it regress? It's difficult to say. As a team, the Marlins have decent plate discipline, but they're not contact-oriented. I imagine the offensive philosophy is summed up like this: "Be selective; however, when you get your pitch, swing the living daylights out of the bat". By the end of this season, perhaps the Marlins could sink down into a dank cellar. For now, I'll enjoy the wine.

Here's Neil Paine of FiveThirtyEight:

For one thing, their hitters also lead the league in batting average on balls in play (BABIP), meaning they’ve gotten exceptionally lucky at having the ball fall in for a hit when they’ve made contact. Interpreting hitter BABIP is more complicated than it is on the pitching side because some batters deviate from the norm by quite a bit even over large sample sizes, but Miami’s BABIP is out of step with its batters’ established baselines. Using the Marlins’ actual 2014 balls in play totals, combined with their preseason ZiPS projections (a statistical projection system created by Dan Szymborski), we would have expected the Marlins’ non-pitchers to put up a BABIP of .305 (compared to their actual rate of .335). Remove those 22 extra hits, and the Marlins lose more than a quarter of their run differential.

The first and foremost question regarding the Marlins is the fact that the team leads the league in BABIP. The mark is three points better than the Colorado Rockies' .331 mark, then 16 points better than the team after that. It is extremely unlikely that players like Casey McGehee (.384 BABIP), Jarrod Saltalamacchia (.373), and Adeiny Hechavarria (.357) will continue on the pace that they are going. As Paine mentions, removing those 22 extra base hits from previous expectations and you get a lot fewer runs. The average difference between a ball in play and an out is around 0.7 runs; losing 22 hits would knock 15 runs off of the Marlins' offense and lead to a run differnetial of 10 runs.

But that still leaves Miami floating above water in terms of run differential. Paine's second point was that Miami was getting contributions from players playing above expectations, particularly on offense. Part of the team playing above its head, however, is the BABIP phenomenon that was already discussed. if we just look at it from the preseason projection aspect, however, we can estimate just how many runs better the Marlins' offense has been thus far this season compared to their expected results.

The following list shows the preseason projections for the top 12 lineup performers by plate appearance and shows the difference in runs produced versus expected in this amount of playing time.

In total, Miami's top nine performers with over 60 plate appearances hit a combined .352 wOBA as a team, when they were expected to hit a .320 wOBA combined. In total, that translated to a bonus of 25 runs better than average so far this year. The biggest perpetrators are Saltalamacchia and his absurd walk rate, Derek Dietrich, and Adeiny Hechavarria. Dietrich is also boasting a renewed walk rate, while Hechavarria's gains are almost entirely BABIP-related.

If you take those 25 runs away, Miami ends up at a dead even run differential. That means that, had Miami's offense performed as expected, we would be looking at essentially a .500 team, which is what the Fish are currently performing at. You can also point to gains that the pitching staff made as potentially not holding, which would bring the Fish to underneath a .500 club.

But while some of the runs were BABIP-driven, some could also be due to true development by players. It is unlikely that Saltalamacchia, McGehee, or Jones have figured something new out, but gains by Yelich or Ozuna still hold some promise of sticking, though it is too early to tell. Similarly, on the pitching side, Nathan Eovaldi has shown fantastic growth, while it is unlikely that Tom Koehler continues to beat out his peripherals this well.

Overall, Miami is left where I expected they were when I discussed their April performance: still in limbo and able to go in any direction from here. If players like Yelich, Ozuna, and Eovaldi begin to make real strides towards success, then Miami has a chance to hold onto some of its good play from the early part of the year. If everything is subject to heavy regression to the standards of pre-2014, then we would expect to see Miami sink really far down the ladder. When you average those two possibilities out, you get what FanGraphs is expecting going forward: a .477 win percentage team (equivalent of a 77-win team) that has made some real strides in the first month but still has a ways to go.

That too is exactly where Jonah Keri has Miami in his latest "The 30" weekly power rankings piece.

As such, here’s a quick explainer for this week’s file: While I’m weighing records, run differentials, and trends more now than in Week 1, I’m still putting ample weight on roster quality.

Try Again Later

If you’re looking for teams that could see big swings in either direction from here on out, you’ve come to the right place.

24. Toronto Blue Jays (14-17, 0, LW: 22)
23. Pittsburgh Pirates (12-19, -15, LW: 18)
22. Chicago White Sox (15-17, −4, LW: 21)
21. Cleveland Indians (13-18, −18, LW: 16)
20. Seattle Mariners (14-15, −2, LW: 24)
19. New York Mets (16-14, -2, LW: 20)
18. Miami Marlins (16-15, +24, LW: 27)
17. Cincinnati Reds (15-16, +17, LW: 17)

As Paine does, Keri considers prior roster quality in his rankings, and he has seen enough to move Miami, at least for now, into the middle of the pack, which is exactly where FanGraphs is expecting them to finish.

No, Miami should not do better than their current .500 mark going forward. But it is very likely that this past month-plus of baseball has officially sunk the likelihood that Miami is a cellar-dwelling catastrophe a la the Houston Astros. This year's Marlins, for whatever reason, are improved over last year's club, and it goes beyond a streak of BABIP luck. There is legitimate improvement, but obviously not yet enough to show contender status in a stacked division.

Marlins fans will take that gladly.