February 23, 2006

The Player Forecast Manager

Tips and Tools

by Ben Murphy

One 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:

• League Type: this allows you to specify if you're using rotisserie or points scoring system in your league; please note that rate stats will not be allowed to carry point values in the PFM, so if you select points scoring, rate stats will not display and will not be part of the points calculation
• Draft Type: this allows you to specify if your draft is an auction or a straight draft (this includes snaking straight drafts); this will only affect the ways you input the inflation values: in the auction choice, you will be given text boxes to enter the dollar value a player is at; in the straight draft choice, the inflation values will always be zero, so you are given buttons to click to save time
• League Used: this allows you to select the player universe that your league settings use: AL, NL or both
• Disposition: allows the user to select from between a more conservative and a more aggressive approach when deriving dollar value calculations; the more aggressive approach places a higher value on the top players (e.g., "Stars & Scrubs")
• Use Positional Adjustment: adjusts position player dollar values upward or downward based on an estimate of replacement level at a player's respective position given the parameters of the league; we recommend that the positional adjustment be left ON; players who play more than one position are adjusted to the position at which they would be the most valuable
• Use Inflation: allows the user to turn off the inflation feature of the PFM; change this to "No" only if you will never want to use the inflation feature
• Statistics To Use: in the preseason, only the PECOTA forecasts are available, but as the season progresses, options will be available for season-to-date statistics, allowing you to evaluate a player's performance on the fly
• Number of Teams in League: this is fairly straightforward--enter the total number of teams in your fantasy league
• Total Budget: for auctions, this value is set up in the league's draft setup and is typically $260; in the case of a straight draft, the budget dollar values give you a chance to structure how you value hitters and pitchers, but since you won't actually be bidding on players, it is most useful to compare hitters and pitchers
• To Hitters: out of the total budget given above, this is the amount you would spend on hitters; please note that this setting and the total budget setting can have a drastic effect on how the dollar values come out
• To Pitchers: this is shown for convenience and is calculated as total budget minus hitter budget whenever one of those two is changed; this is representative of how much money you expect to spend on pitchers
• Minimum Salary: in auction leagues, each player must have a certain minimum salary; enter that value here
• Minimum Games Played: determines the threshold for number of 2005 games played in order to render a player eligible at a given position; this will have an impact on dollar values if you have the Positional Adjustment turned ON
  At this time, PFM does NOT provide functionality for players who may become eligible at new positions during the course of the season. Please note that if the player did not get enough playing time in MLB at any position to eclipse the minimum games played, the position is taken from the Depth Charts
• Minimum Dollars/Points Displayed: this option is new in 2006 and allows you to control the lowest value to be displayed after calculations have been made; this is offered as a convenience to help you screen out players and speed processing time; please note that the default value of zero will tend to keep some interesting prospects or players with poor forecasts from being displayed and many users will find a value like -10 or -25 for this option to give more useful results
• Show Playing Time: this option is new in 2006, at least for the Web version of the PFM; we had so many requests for this option that it has been recently added; if turned on, this will display PA, AB and IP for hitters and pitchers as long as they are not already scoring categories

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.