The Pirates' offense has been the best in the National League over the last 30 days, and it is close to overtaking the Dodgers for the most productive offense overall (based on wRC+). The offensive turnaround has led the surging Pirates to a 17-10 record in their last 27 games.
Will the offensive resurgence continue?
There are a couple of ways to approach this question, but at some point it boils down to either trusting the performances we've seen so far and assuming they'll continue, or placing more weight on the rest of season (ROS) projections.
Last week on Fangraphs, David Cameron, piggybacking on a post written by Mitchel Lichtman, argued that we should "trust" ROS projections more than early season performance. Cameron and Lichtman show that ROS projections are much more reliable indicators of future performance than what a player has done through the first 60-plus games. Cameron concludes, "The evidence suggests the conservative path, leaning almost entirely on forecasts and putting little weight on seasonal performance, is the one that is wrong the least."
Below is a run calculator that allows you estimate the remaining the runs that the Pirates' offense will produce this season using ROS projections, 2014 performance, and your own unique projections. In essence, you can figure out whether you think the offense is sustainable and how many runs the Pirates should score the rest of the way.
The calculator works by transforming the statistic wOBA (weighted on base average) into wRC (weighted runs created).
If you are unfamiliar with wOBA, think of it as OPS, but better. It is based on the same scale as on base percentage (OBP), so what looks like a good OBP is a good wOBA, and vice versa.
The columns explained. (You can edit every column):
PA: an estimate of remaining plate appearances based on Fangraphs projections. You can edit this to match your own projections of playing time. Gregory Polanco's looks like an obvious one to change. Just remember you want to end up with about 3600 total PA remaining for the season. If you don't, the expected runs will be off.
Fangraphs: Fangraphs projected ROS wOBA
2014: current wOBA
You: input your own wOBA projections
Yellow area: the projected runs created based on plate appearances and wOBA for each projection.
Bottom: the total team runs created
Total runs calculator
Below the projection calculator is a total runs calculator. Simply put in your estimated runs from the projection calculator into the area "Final 93 G," and total runs for the season will be calculated.
Some numbers to compare your projections to:
2013 Pirates = 634 runs scored
2013 Boston = 853 (most runs scored in MLB)
2013 St. Louis = 783 (most runs scored in NL)
2013 National League average = 649 (675 MLB average)
According to Fangraphs' projections, the Pirates' offense can be expected to generate 388 more runs this season. They would add 391 more runs if each player continued to perform exactly has they have so far.
Based on Fangraphs projections, the Pirates are expected to score 687 runs this season, which is 53 more than last season. It would also be above MLB average runs scored last season.
(REMEMBER: you can edit plate appearances to reflect what you think actual playing time will be. You can edit everything in the calculator.)
Who will improve? Who will drop off?
Finally, here are some graphs that compare 2014 performance to ROS projections.
Russell Martin, Gaby Sanchez and Neil Walker are expected to drop off the most offensively, while Jordy Mercer and Ike Davis are projected to contribute more.
Now, the outfield:
Andrew McCutchen, Gregory Polanco and Josh Harrison are obviously expected to cool off some, while Starling Marte improves slightly.