This is an idea I’ve been mulling over for some time now. How do you determine the overall fantasy value of a player? Is there an objective measure of their value in the 5×5 categories that could allow you to value them correctly? It’s not as simple as adding up runs, HR, RBI and stolen bases. What I mean is this: because stolen bases are relatively rare compared to the other categories, each one is more valuable than just one of each of the other stats. If there were a way to weight each category, you could judge whether getting player A, who has a great batting average, is worth the tradeoff over player B, who has more balanced production.
One solution I had to this conundrum was to use percentile ratings for each scoring category. Because 2007 was a very different looking statistical year from 2005 or 2006, I used every player who had at least 250 AB in 2007 (there were 306 of them) to generate percentiles (broken down into every 10%) for each category, which you can see below:
Percentile BA R HR RBI SB
90 .320 100 28 101 24
80 .297 87 22 87 13
70 .290 80 19 74 9
60 .283 71 16 66 5
50 .275 60 12 60 4
40 .266 54 10 51 3
30 .259 47 8 45 2
20 .251 40 6 38 1
10 .236 33 3 31 0
For example, regardless the identity of the players, the top 10% of players in the HR category hit at least 28 HR, and the top 20% of base stealers swiped at least 13 bases. Now, using projections for 2008 (I used the freely available CHONE 2008 v2 projections) and using this scale, we effectively get a “rating” for each player in each category. These ratings in each category can be totaled, and the result is a list of hitters’ projected overall fantasy value. I think you’ll agree that the method works pretty well, based on the top 20 players I got from this first run:
Tier 1 Albert Pujols
Alex Rodriguez
David Wright
Matt Holliday
Tier 2 Prince Fielder
Miguel Cabrera
Vladimir Guerrero
Chase Utley
Ryan Braun
Hanley Ramirez
Carlos Lee
Tier 3 G Sizemore
A Soriano
J Rollins
Tier 4 D Ortiz
C Jones
C Beltran
N Markakis
Tier 5 L Berkman
M Teixeira
Of course, everything rides on the quality of the projections you use. You would get a different ordering by using another projection system. The results lend themselves well to a closely tiered system. I think that generally reflects reality, so that you could say that any player within a certain tier could easily outplay the others with a good year.
Pitchers are a little bit trickier, because starters sometimes become relievers, and relievers often make spot starts. It’s difficult to decide where the cutoff should be. Secondly, predicting wins and saves is notoriously difficult. Still, here are the derived percentiles for starters and relievers from 2007 (SPs had at least 10 GS and pitched 100IP, relievers had to pitch at least 30 innings to qualify):
Percentile W K ERA WHIP
90 16 183 3.33 1.19
80 14 163 3.70 1.24
70 13 141 3.88 1.30
60 11 131 4.12 1.34
50 10 114 4.40 1.38
40 9 104 4.63 1.41
30 8 93 4.94 1.48
20 7 78 5.21 1.54
10 5 64 5.70 1.60
CHONE does not even try to predict wins, because it’s so hard to do. So what I did is I took the mean of the Bill James and Marcels projections for wins, and rounded to the nearest whole number. So without further ado, here are the top 15 starters, ranked:
- Jake Peavy
- Johan Santana
- C.C. Sabathia
- Dan Haren
- Cole Hamels
- Scott Kazmir
- Josh Beckett
- Aaron Harang
- Brandon Webb
- John Smoltz
- John Lackey
- Roy Oswalt
- James Shields
- Chris Young
- Javier Vazquez
The picture is slightly different for the relievers:
Percentile W Sv K ERA WHIP
90 6 21 78 2.35 1.02
80 5 6 64 2.88 1.15
70 4 2 57 3.10 1.24
60 3 1 51 3.54 1.31
50 2 0 46 3.88 1.36
40 1 0 41 4.28 1.44
30 0 0 36 4.72 1.52
20 0 0 30 5.16 1.61
10 0 0 26 5.83 1.74
I had to do the same kind of deal for wins and saves with the bullpen guys using Bill James and Marcels projections. Top 10 relievers:
- J.J. Putz
- Huston Street
- Takashi Saito
- Jonathan Papelbon
- Francisco Rodriguez
- Matt Capps
- Billy Wagner
- Joe Nathan
- Mariano Rivera
- Rafael Betancourt
This was a huge list of pitchers, 140 “starters” and 213 “relievers”. In applying the rating system, I tried to value all pitchers on the same scale, not separately, so I used the starters’ scale for wins and strikeouts, because the contributions of a relief pitcher in those categories must approach those of a starter to be truly useful. The combined list seems to favor relievers a little too much, but all in all, not a bad first pass. Because this percentile system is done for each category individually, I think I could even combine the hitters and pitchers list to get an overall ranking eventually that wouldn’t be too out of whack with reality (fantasy reality…uh, yeah).
I’ll be the first to admit it needs some pretty major tuning, and ideally we would use a blend of projections for the most accurate rankings, but you get the idea. Please tell me what you think!