THT Projections: A (Quick) Closer Look

by
March 7, 2007

Earlier this week the much anticipated Hardball Times 2007 Season Preview was released, and with it a brand new projection system. I recently took a look at Bill James, CHONE, ZiPS, and the Marcel projection systems to see how they differed. Let’s throw THT into the mix and see where it has its major differences.

First off, let’s see how THT fares against the other projection systems in OPS and ERA as a whole when compared to the Marcel projection system (the simplest of the five).

System        ERA-R^2    OPS-R^2
ZiPS             .725       .908
Bill James       .714       .875
CHONE            .699       .865
THT              .681       .837

And in English, when comparing the other projection systems to the Marcel projection system, THT’s system is the least similar. (When look at batters with 300+ at-bats and pitchers with 100+ innings.)

So which batters does THT disagree on the most in terms of OPS?

Name            Bill James    CHONE   Marcel     THT    ZiPS
Frank Thomas          .939     .853     .874    .982    .892
Hanley Ramirez        .801     .791     .843    .714    .777
Robinson Cano         .860     .842     .852    .766    .836
Chris Duncan          .862     .776     .891    .753    .803
Melky Cabrera         .766     .796     .787    .715    .800

Except for Frank Thomas, who THT projects is going to have a phenomenal season, they’re the low point for the other four players. It’s interesting to note that those four are also first or second year major league players. There’s generally a lot of disagreement about Chris Duncan and Hanley Ramirez, but the THT projections for Robinson Cano and Melky Cabrera appear to be the sole point of difference. Let’s look at the pitchers:

Name            Bill James    CHONE   Marcel     THT    ZiPS
Tony Armas Jr.        4.85     4.64     4.96    5.81    4.88
Carlos Zambrano       3.40     3.47     3.48    2.77    3.46
Cliff Lee             4.43     4.20     4.48    5.04    4.55
James Shields         4.03     4.29     4.72    5.03    4.70
Brandon Webb          3.53     3.60     3.65    3.07    3.85
Randy Johnson         4.31     3.77     4.33    3.43    3.63

THT clearly hates Tony Armas Jr. (more) with his ERA about a point higher than the others, while they love Carlos Zambrano who they have at about a .75 lower ERA than the other systems. I threw in Randy Johnson since he was next on the list. It looks like the projections are pretty well divided for him between the 4.30-ish ERA, and the 3.50-ish ERA.

You Aren't a FanGraphs Member
It looks like you aren't yet a FanGraphs Member (or aren't logged in). We aren't mad, just disappointed.
We get it. You want to read this article. But before we let you get back to it, we'd like to point out a few of the good reasons why you should become a Member.
1. Ad Free viewing! We won't bug you with this ad, or any other.
2. Unlimited articles! Non-Members only get to read 10 free articles a month. Members never get cut off.
3. Dark mode and Classic mode!
4. Custom player page dashboards! Choose the player cards you want, in the order you want them.
5. One-click data exports! Export our projections and leaderboards for your personal projects.
6. Remove the photos on the home page! (Honestly, this doesn't sound so great to us, but some people wanted it, and we like to give our Members what they want.)
7. Even more Steamer projections! We have handedness, percentile, and context neutral projections available for Members only.
8. Get FanGraphs Walk-Off, a customized year end review! Find out exactly how you used FanGraphs this year, and how that compares to other Members. Don't be a victim of FOMO.
9. A weekly mailbag column, exclusively for Members.
10. Help support FanGraphs and our entire staff! Our Members provide us with critical resources to improve the site and deliver new features!
We hope you'll consider a Membership today, for yourself or as a gift! And we realize this has been an awfully long sales pitch, so we've also removed all the other ads in this article. We didn't want to overdo it.

Anyway, the THT projections are certainly similar to the others, but there are clearly a number of key differences which are definitely worth a look. There’s also a lot more to projections than ERA and OPS, so I’m sure you’ll find many other unique aspects to THT’s projection system. Like with any projection system, we’ll have to wait and see which one happens to be the most accurate for 2007.





 

David Appelman is the creator of FanGraphs.

5 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
tangotiger
18 years ago

I would drop the threshhold for pitchers to 60 IP, or even 50 IP. Otherwise, you are essentially only looking at starters.

Or, you can not have a threshhold at all, and simply do:
sum(PA * abs(Marcel minus x) ) / sum(PA)
where PA is the PA or IP in system X, and “x” is OPS or ERA of system X

This will neatly bypass the issue of selective sampling.

You should further, if you want to be fair, do this:
The OPS of Jeter under Marcel would be: his OPS minus the league OPS that Marcel expects. Repeat for each of the systems. And to figure the league OPS, you would take the forecasted OPS and PA of each system in question.

0