In case you haven’t yet noticed, a trip to team depth charts and individual PECOTA cards now features what is commonly referred to as in-season projection updates. A fantastically useful addition to the site, the updated PECOTAs incorporate data accrued this season and, through a nifty little process that will be outlined below, blend with the pre-season projection in order to inform on expectations for a player moving forward. Keep in mind when reading about the in-season update process that the actual PECOTA cards for individual players have not been altered save for a brief table beneath the player’s picture with the update itself; the vast majority of the original card has remained intact.
Clay Davenport utilizes his translations to make the updates, and instead of providing you with a laundry list of random steps, let’s instead discuss the new system through an example… say, Joe Mauer, since we recently discussed his chances at hitting .400 (score +1 for Seidman in the self-pimping column!).
Prior to the season, Mauer had a weighted mean projection of .307/.388/.436, based on aspects such as his track record, his age, expected park factors for the league, expected league performance, and the list goes on. The first step to providing his in-season projection involves the retranslation of his pre-season PECOTA to the external factors inherent in 2009. For instance, partly due to Minnesota running a park factor of 1.06 as opposed to the expected 0.98, and partly due to the current offensive levels of the junior circuit, Mauer’s retranslation of the original PECOTA jumps to .313/.402/.457; as in, if we expected Minnesota to boast that specific park factor entering the season, Mauer’s weighted mean would have looked like the aforementioned triple-slash line, not the original line atop this paragraph.
The next step involves translating Mauer’s 2006-09 seasons relative to the 2009 specifications, or, in other words, what his lines in years past would have looked like had they sported similar leaguewide offensive levels and park factors. The translated numbers from 2006-09 are then weighted, decreasing back by one-half each season; 2009=1, 2008=0.5, 2007=0.25, 2006=0.125.
When the weights were run on the translated numbers, a weighted average of .339/.426/.538 results, which then has to be blended with the pre-season projection. The Twins had played 94 games, which accounts for 58 percent of their season, so the weighting would be 0.58*translated weighted average + 0.42*original but translated PECOTA. The end result is a .328/.416/.504 line. Based on what we have seen this year as well as what PECOTA saw in making the original projection, Mauer should hit right around .328/.416/.504 the rest of the season. The way it is set up, the more games played this season, the less weight the original PECOTA carries. From there, raw totals are derived from the playing time estimates in the updated PFM.
So, if you’re ever curious about what a player is projected to do from here on out, simply take a trip to the team depth charts or to his individual PECOTA page. In case anyone isn’t sure where to find it, here is a link to Joe Mauer’s page:
Beneath his picture is a big, blue bolded link titled Projected Playing Time. Beneath that is a short, 3-line or so table with his playing time percentage and rates/raw totals projected from here on out. This is where it can be found on the individual cards. Relative to the team depth charts, click on the link for Projected Playing Time and you will be transported to the team page, with playing time estimates and projections from here on out.