Do you know if the SGP calculations you’ve done for your league are accurate?
Are you concerned that your home run SGP denominator is 8.87 and Larry Schechter’s book Winning Fantasy Baseball suggests using 5.93 for a 12-team league? Or that your RBI calculation shows 22.31 and the 12-team NFBC history I just calculated shows 19.55?
What does this all mean? Will your rankings be accurate? How can they be when your denominators seem significantly different than those you see elsewhere?
Calm Down, These Numbers Are More Consistent Than You Realize
I know. You’re wondering how on Earth I can say that. How can a HR denominator of 8.87 be consistent with one of 5.93?
To be honest, I’ve had those same fears about SGP. I feel so scientific and strategic by calculating SGP. And then I look at my denominators in comparison to what I see published elsewhere and that confidence evaporates and is replaced with doubt.
In this post I’m going to share an important realization I just had about SGP (yep, I’m still learning too), show you how to properly compare your SGP denominators to different resources, and demonstrate that the dollar values calculated by different sets of denominators are more similar than you would believe. When we’re done here, I think we’ll all feel a lot more comfortable about things.
This story starts with me calculating the SGP for the last three seasons of NFBC leagues (which make their standings information publicly available).
I read Winning Fantasy Baseball a couple years ago (if you haven’t read it and you’re about to read 2,500 words on SGP denominators, you really should get the book), and I vaguely remembered the book giving SGP denominators for a variety of league types. I wanted to verify that my findings were similar to Schechter’s.
Here’s what I found:
|2015 12-team NFBC Online Championship||0.00180||19.92||8.43||19.55||7.59|
|Winning Fantasy Baseball 12-team League||0.00165||15.52||5.93||16.30||5.93|
Damn. WTF does this mean? Those don’t look close to me. Did I do something wrong?
A Very Important Point
As I looked more closely at the book, I noticed I missed a very important point the first time I read it. Next to each number, Schechter had calculated a “relative SGP value”.
|Raw SGP Denominator||0.00165||15.52||5.93||16.30||5.93|
|Relative SGP Denominator||n/a||1.05||2.75||1.00||2.75|
And here’s the important point Schechter makes about these calculations:
… when you’re trying to adjust SGPs for leagues of various sizes, it’s important to realize that the raw value of the SGP isn’t very important, but rather the ratio of the values.
~ Larry Schechter, Winning Fantasy Baseball
Mine Is Bigger Than Yours Is
I glossed over that red bolded sentence on previous reads (because it’s not bolded red in the book…). But this small statement buried in the middle of the 350-page book is exactly the point I needed for the self-doubt I was experiencing.
So in order to hopefully save you the same trouble, take note! You can’t compare your SGP denominators to someone else’s. You have to convert them to a relative scale first.
Raw Versus Relative – An Example
Let’s focus in on just the HR and RBI stats from the table above.
|Raw SGP Denominator||5.93||16.30|
|Relative SGP Denominator||2.75||1.00|
If it takes 16.30 RBI and 5.93 homers to move up the standings, this essentially means that one home run is 2.75 times more important than one RBI (home runs are more scarce, so getting one of those is more valuable than the more common commodity, RBI).
16.30 / 5.93 = 2.75
16.30 / 5.93 = 2.75
Do you remember working with fractions in elementary school? I liken this practice to that whole “lowest common denominator” charade we had to go through. Dropping the SGPs to a relative scale is like converting them to a lowest common denominator. If you leave the SGP factors grossed up at these high numbers (like 5.93 and 16.30), it’s more difficult to see the relationships you can see when they’ve been translated into the relative scale.
One More Math Concept
If you read Using Standings Gain Points to Rank and Value Fantasy Baseball Players or if you’re generally familiar with the SGP approach, you know that we would divide a player’s home run total by the home run “SGP denominator” to know how many SGP the player contributes due to his homers.
For example, if a player is projected by 30 home runs, an SGP denominator of 5.93 would indicate the player’s homers are worth 5.1 points in the standings (30/5.93=5.1). If the same player is projected for 83 RBI, an SGP denominator of 16.30 suggests the RBI are also worth 5.1 SGP (83/16.30=5.1). The 30 HR are worth the same as 83 RBI (5.1 SGP).
However, the way Larry Schechter has calculated his relative SGP would require you to multiply a player’s stats to achieve that same equality. For example, the 30 HR multiplied by 2.75 is 83 “points”. The 83 RBI multiplied by 1.00 is also 83 “points”. The 30 HR are worth the same as 83 RBI (83 relative SGP).
For Consistency, I Will Calculate Relative SGP Another Way
If you look back at the big bolded numbers above, Larry Schechter used the largest statistic (RBI for hitters and K for pitchers) as the numerator in his conversion. I will use it as the denominator.
5.93 / 16.30 = 0.364
5.93 / 16.30 = 0.364
I’m mostly doing this because everything I’ve written about SGP to this point tells you to DIVIDE BY THE SGP DENOMINATOR (heck, it’s called a denominator, meaning it’s on the bottom of the fraction). To now tell people to MULTIPLY BY THE RELATIVE SGP DENOMINATOR seems too confusing to me.
I’m sure I’ve confused the hell out of everyone at this point either way. And I apologize for this. But I think this topic is very important to understand. I’m giving it my best! Even if you’re confused, keep reading. I think this will all pull together very nicely in the end.
Going back to our example of a player with 30 HR and 83 RBI, if I divide by an SGP denominator of 0.364 I get that same 83 “points” (forgive the rounding), meaning the 30 HR are worth the same as the 83 RBI under this approach. So whether you use Schechter’s relative numerator and multiply or my relative denominator and divide, you get the same results.
How to Calculate “Relative” SGP Denominators
I’ve talked a lot about multiplying and dividing. So just to be clear, to put your SGP denominators on the same relative scale, choose the category with the largest numeric value, then divide each stat categories raw SGP denominator by that largest raw SGP denominator.
The largest numeric denominator is typically RBI for the hitting categories (the 16.30 from above is the largest SGP denominator) and strikeouts for pitching.
For the rest of this post I will be using this calculation of relative SGP denominators and NOT the way suggested in Winning Fantasy Baseball.
My NFBC Relative Versus Winning Fantasy Baseball’s 12-team Relative
Using the method described above, I calculated the relative denominators for Larry Schechter’s 12-team suggestions and my 2015 NFBC findings. Here are the results:
First look at the white lines. These give me that queasy feeling I was describing earlier. He’s saying 5.93 HR for a 12-team league? And I came up with 8.43? That’s 2.5 HR difference. How can these suggestions even be in the same ballpark?
Now look at the yellow-shaded lines. After everything is put on the same scale things look a lot more reasonable. When you look at all items on a relative scale, you can see many of the categories are strikingly similar (BA, R, RBI, SB, K, SV), but still show small variations. There is some variance in the other categories, but things don’t look as stark as with the raw denominators. This supports our beliefs about SGP being able to “tailor” to our league tendencies and preferences, but still leaves me feeling a lot more comfortable that my denominators are in fact closer to Larry Schechter’s than it appears on the surface.
Right around this time I’m starting to feel more comfortable with my analysis. But I’m also very curious about what happens if I start looking at SGP denominators from other sources. So I set out to find as many sources as I could find.
NOTE: After publishing this article, it came to my attention that there’s a typo in Winning Fantasy Baseball that makes this last segment somewhat less relevant. I’ve elected to keep it in despite this.
— Larry Schechter (@LarrySchechter) January 23, 2016
Other SGP Denominator Sources
The reliable sources I was able to locate for this analysis are:
- My Own Home League (has varied from 11- to 13-teams)
- Winning Fantasy Baseball (12-team league)
- Winning Fantasy Baseball (15-team league)
- Information Published by Razzball in 2012 (12-team league)
- 2015 NFBC Online Championship (12-team league)
- 2015 NFBC Draft Championship (15-team league)
- 2014 NFBC Online Championship (12-team league)
- 2014 NFBC Draft Championships (15-team league)
- 2013 NFBC Online Championship (12-team league)
- 2013 NFBC Draft Championship (15-team league)
- Jeff Zimmerman’s 2015 Draft Prep Series (Actual, 15-team league)
- Jeff Zimmerman’s 2015 Draft Prep Series (Adjusted, 15-team league)
- Jeff Zimmerman’s 2014 Draft Prep Series (12-team league)
Not bad. I was able to scrape up 13 different resources for comparison. And I threw in the average of those 13 resources as my 14th.
Here’s the Raw SGP Data
You can see things are all over the map. You can see general patterns, but the data fluctuates wildly. Some of the raw SGP denominators are almost double others. For example, Larry Schechter’s 12-team HR denominator is 5.93 while Razzball’s 2012 article calculated a 10.40!