As we get ready for the second half of the baseball season to begin tonight, I thought it would be interesting to examine whether the Pirates' performed to preseason projections in the first 85 games. We'll get right to the numbers after the jump.
What I did
Using ZiPS (Szymborski Projection System) I calculated the projected statistics for each player on the Pirates adjusted by their actual number of plate appearances (innings pitched) this season. I then summed the totals to derive what I'm calling the "ZiPS Pirates."
Example: For Andrew McCutchen I first calculated his projected rate of singles, doubles, triples, home runs, walks, strikeouts, etc., per plate appearance (projected doubles divided by plate appearances). I took those rates and multiplied them by the actual number of plate appearances. So, ZiPS projected that Andrew McCutchen would hit .052 doubles per plate appearance. When I multiplied .052 by his actual plate appearances, 343, I ended up with 18 doubles for him (he has 17 actual doubles). I did this for each player and then summed the results (I added in the actual offensive numbers for pitchers.)
The table below compares the offensive statistics of the ZiPS Pirates to the Actual Pirates.
(Click to enlarge)
The slash numbers (AVG/OBP/SLG) are right around the projected rate. The strikeout and home run totals stand out as the biggest difference. The Pirates have both struck out and hit many more home runs (19 percent more) than projected.
In terms of scoring runs, the ZiPS Pirates score about 16 more runs than have the actual Pirates.
("EFF Runs" is weighted Runs Created multiplied by the Pirates offensive efficiency rate this season, which is 108 percent. In other words, the Pirates have scored about 8% more runs than their straightforward offensive statistics would suggest. The "EFF Runs" for the Actual Pirates is their actual number of runs scored; for the ZiPS Pirates it is their wRC multiplied by 1.08. For more on offensive efficiency and what it means, follow this link.)
The table below compares the pitching statistics of the ZiPS Pirates to the Actual Pirates.
ZiPS did not project the Pirates to pitch as well as they have so far this season. While the home run and strike out rates are dead-on, the hits allowed and runs scored are very different. The ZiPS Pirates give up almost a full run more per game. (I calculated runs for the ZiPS Pirates by multiplying earned runs by the current unearned runs rate of the actual Pirates.)
Using the run scoring numbers from the projections, I calculated Pythagorean records based on different combinations of ZiPS and Actual Pirates.
ZiPS Pirates = The record of the projected Pirates.
ZiPS (Eff) = The record of the projected Pirates with a offensive efficiency of 1.08 factored in (i.e. wRC*1.08).
zDEF/aOFF = The record of the Pirates with ZiPS pitching and actual offense
zOFF/aDEF = The record of the Pirates with ZiPS offense and actual pitching.
Finally, I graphed the difference between projected and actual OPS for each of the core players on the team. I included the numbers from May 26th comparison's sake. It is after that date that the Pirates' offense began to steadily improve. .
The yellow bar is the player's OPS on May 26. The red bar is the ZiPS OPS. The black bar is current OPS.
With the exception of Barajas and Harrison, every core player has improved their OPS since May 26.
In the graph below zero is the projected OPS for each player. Bars below (above) zero mean the player is performing below (above) projection. The numbers in the data table at the bottom of the graph are the difference between projected OPS and actual OPS.
With the exception of Michael McKenry and Andrew McCutchen, every player's OPS is closer to his projected OPS than it was on May 25th.
With the exception of McKenry and McCutchen, who are both outperforming their projections by a significant amount, and Clint Barmes who is under-performing, most players are currently right around their projected OPS
So, what does this tell us?
The Pirates offense is performing right around where preseason projections would have them. The pitching is outperforming projections by a significant amount. If the offense repeats its performance in the second half and produces right around projected level, the pitching/defense will need to continue to outperform projections for the Pirates to continue to win at an above .500 pace.
However, if the pitching regresses to preseason projected levels, and the offense replicates its first half performance, we would expect around a .435 winning percentage, or 33 additional wins. Fortunately there doesn't seem to be much reason to be concerned with a pitching catastrophe in the second half. Besides likely regressions from the bullpen and Kevin Correia, there isn't much reason to fear a significant drop-off.
That's it for now. Baseball is finally back tonight! Enjoy the second half of the season.