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February 23, 2006
The Player Forecast Manager
Tips and ToolsOne of the most interesting projects I've gotten to be a part of since I've been here at Baseball Prospectus is the Player Forecast Manager (PFM for short; PFM could also mean PECOTA Fantasy Manager). The PFM was originally designed by Nate Silver to help users calculate appropriate dollar values for fantasy baseball leagues that use auctions to distribute players. PFM values are built off of the concept of replacement level, scaled and applied to the fantasy baseball world. The PFM figures out hypothetical replacement level at each position for each statistic that your league uses, then assigns players credit for how far they surpass the replacement level in each statistic, both with respect to their position and with respect to the rest of the players.
New to PFM this year is support for points leagues, some ease-of-use features for people in a straight draft (as opposed to an auction draft), and the ability to download the statistics to a tab-separated or comma-separated text file. Previously, we didn't have the option to display playing time in the web based PFM (it was an option on the original Excel-based version).
This system has helped many Baseball Prospectus readers win their fantasy leagues, including myself. This year, we have made a few notable improvements to the PFM, so to help those of you who aren't familiar with the tool, I'd like to introduce some basic usage tips, point to useful options, and hopefully get everyone acquainted with one of the best draft tools available.
The PFM works in two main stages. The first stage is where you specify your league settings and the second is where you get the player values and can use the inflation tool to adjust the player values during the course of your draft. In the first stage, there are three categories of settings: personal preferences and league setup, roster specifications and statistic selections (with a column for each hitters and pitchers).
In the first column, you will specify the main options:
In the second column, you'll specify your league's starting roster spots. Typically, the PFM is only used for drafting the starting roster for a team. The values that it calculates are based off of this assumption, so the safest way to go is to have just your starting roster put into the PFM's settings. However, if you want to assume that teams will always split their bench spots a certain way, say 10 bench spots split as 5 hitters and 5 pitchers, you might try adding 5 more Util hitters and 5 more pitchers. This is a somewhat risky assumption, but it could help you get a better feel for the value of these bench spots as a result. Officially, though, this section is for your starting rosters only.
The third and fourth columns comprise the third section, where you use the checkboxes to indicate which statistics your league uses for scoring. Please note that the PFM does not support having rate stats in points leagues, but otherwise any statistic is fair game.
Once you submit all the settings and get a listing for players, you can use the draft inflation tool during the draft to account for which players are taken and how much they were drafted for. This applies primarily to auction drafts, where the players will be auctioned off for a salary value. In a straight draft, the inflation tool will expect dollar values of zero for every taken player and it will inflate the remaining available players accordingly. This means that toward the end of the draft, when there are relatively few players remaining to be drafted, the inflation tool might cause PFM to give erratic results.
Some of the things that tend to trip people up are the default settings and budget constraints. For example, the default value for minimum dollars/points displayed is set to zero, which means that players with dollar or points values below zero are not displayed by default. Many users for roto leagues will probably want to see some of the negative-valued players, so some users might find a value like -10 or even -25 more suitable for this option. Additionally, the default settings are configured to what we think is a typical roto league, which includes the roster setup and budget. Many leagues have smaller rosters, so it might be prudent to rethink how you want your budget allocated. Most users want to have more money allocated to hitters, so a user in a roto league with a roster that only starts C, 1B, 2B, 3B, SS, LF, CF, RF and seven pitchers would probably want to adjust the total budget to something like $100, with maybe $60 to hitters. In fact, I have found it much easier to use a total budget of $100 for most of my straight draft roto leagues. Unless I have a certain specific budget as set up in an auction league, this allows me to see each dollar value as a percentage of that $100 total budget, and any math I want to try to do in my head is that much easier.