Fantasy Value Above Replacement for Pitchers

In previous posts I explained fantasy value above replacement (FVAR) for hitters.  Now I’d like to walk through the steps for calculating pitcher FVAR.  Pitcher FVAR is quite different than hitter FVAR for several reasons that I’ll get into as we go through the process.  All of the examples below assume a standard 5×5 mixed league with 12-teams (based on settings for a Yahoo! Pro League with rotisserie scoring).  For pitchers that means a cap of 1,400 innings pitched (IP) and the following roster spots for pitchers: 2 SP, 2 RP, 4 P, and I also assumed 3 bench pitchers.

Position Eligibility

There are only three positions for fantasy pitchers; SP, RP and P.  I assume the following criteria for eligibility as SP or RP:

• SP eligibility: start at least 5 games in a season or the prior season.
• RP eligibility: make at least 3 relief appearances in a season or prior season.

For hitters it was important to determine a positional hierarchy (i.e., a player eligible as a C and OF would be considered a C because of position scarcity).  However, the approach I’ve taken for pitchers makes position eligibility less important, as discussed below.

Calculating Z-Scores

I explained the concept of z-scores in my first post.  For hitters I used zz-scores (i.e., z-scores with counting stats on a rate per plate appearance).  I tried the same approach for pitchers but it results in much higher zz-scores for RPs, and then the problem of setting an appropriate innings cap and replacement level for SPs and RPs was very complicated (and arbitrary) from year to year.  For these reasons I’ve used z-scores for pitchers.  Z-scores work nicely for comparing SPs and RPs because the RPs get credit for generally having better rate stats, but the SPs get proper credit for pitching more innings.  When using this approach it’s good to keep in mind that it punishes some excellent SPs who pitched fewer innings, for example Tony Cingrani in 2013, and unduly rewards some mediocre SPs who pitched a lot, for example Bronson Arroyo in 2013.

Determining Replacement Levels

Because the z-score approach does a good job putting SPs and RPs on a level playing field they don’t require separate replacement levels.  Furthermore, with just as many flexible P roster spots as SP and RP spots, the distinction is less important for managing a fantasy team.  Also, unlike hitters a SP on the bench can be utilized to his full potential by rotating guys in and out when they’re starting.  Therefore, the key data point for determining pitcher replacement level is the 1400 IP cap.

However, instead of using 1400 IP as the innings cap to determine replacement level we need to consider the very real value of streaming pitchers.  As I showed in my last post, it’s possible to stream at least 2,500 innings at a level well above replacement, which represents about 15% of the league innings cap (2500/(1400*12) = 14.9%.  Think of streaming as a public good or renewable resource that no one owner can own or monopolize, hence it’s fantasy value that doesn’t show up when we look only at season stats.  For this reason, I took 15% off the IP cap and thus assumed that each 12-team league needs to fill 14,280 innings.  For seasons before 1998, I adjusted the number of fantasy teams per league to account for the smaller size of MLB, as shown in my first post and in the table below on F$/FPAR.

Similar to the way replacement levels were determined for hitters, I started by calculating z-scores for every pitcher from 1901-2013.  Then I ranked them within season and added up their cumulative innings.  The pitcher who crossed the innings cap was designated as the replacement for that season and his z-score became the replacement value.  What I found is that the replacement level has dropped over time, meaning the above-replacement level pitchers are having a tougher time separating from league average.  My hunch is that this has a lot to do with the increasing use of RPs in specialty roles.

Here are two charts to illustrate the point.  The first shows the share of innings pitched by SP and non-SP eligible pitchers.  The second shows the replacement level z-score over time.  You’ll see that as the use of SPs has gone down, so too has the replacement level dropped.  (Note that I haven’t made efforts to weed out the strike years of 1981 and 1994).

Image may be NSFW.
Clik here to view.

Image may be NSFW.
Clik here to view.

Because the replacement levels bump around so much from year-to-year I used the calculated value for each year, meaning I didn’t assume a constant or smoothed-out replacement level over time as I did for hitters.

Calculating FVAR

Calculating FVAR was as simple as subtracting each pitchers z-score from the replacement level z-score in that season.  Nothing more required.

Calculating Fantasy Points Above Replacement (FPAR)

As discussed in a previous post, it was justifiable to simply assume that one FVAR point is approximately one FPAR.  For pitchers the conversion was not as convenient because the sum total of FVAR bounced around more from season to season.

For a 12-team league there are 330 pitching fantasy points (FO) up for grabs. However, the ability to stream pitchers takes about 5 FP (or 1.5%) off that total (I won’t go into the details of that calculation, but basically if you take the stream discussed in my previous post and divide by the number of teams you get a pitcher worth 0.4 FPAR and 0.4 times 12 teams equals 5 FPAR).  In 2013 total pitcher FVAR was 283.  Thus, to reach the league total of 325 FP, each FVAR was worth about 1.15 FPAR.  Looking at the numbers from 1901 to 2013, FP/FVAR averages about 1.0, but it bounces around within a range from about 0.8 to 1.2.  To balance the books each year I used the calculated FPAR/FVAR for each season, rather than assuming a constant value over time.

Calculating Fantasy Dollars (F$)

As explained previously, I assume teams in an auction draft will spend $160 for hitters and $100 for pitchers.  The ability to stream pitchers is one darn good reason this strategy makes sense.  To determine F$ for pitchers I simply divided the league pitching budget of $1200 by league FPAR to get F$/FPAR. The following table shows how the numbers work out over time.  For this reason, when comparing hitters from different eras in baseball history it’s best to use FVAR instead of F$.

Best Fantasy Pitcher Seasons of All-Time

Below are the ten greatest fantasy pitching seasons of all-time based on FVAR.

Featured Image courtesy of www.fannation.com

The post Fantasy Value Above Replacement for Pitchers appeared first on Batting Leadoff.