FBM Musings: Crowd Wisdom or Crowd Think?
Simply Aggregate or Assimilate.
Did your parents ever tell you not to hang out with the wrong crowd? They didn’t want you associating with kids that were “troublemakers”. You’re so impressionable at that young age. They probably worried that you might be negatively influenced by bad behaviors.
Is there a “wrong” crowd in fantasy baseball that could influence you negatively?
Well, there can be from a decision-making perspective.
The may appear to be the same, but they are distinctly different.
But, could still be the same if you’re not careful.
✅ Wisdom of the Crowd
In James Surowiecki’s “The Wisdom of Crowds”, the author explains that under the right conditions, groups can make better decisions than individual experts.
The book argues that collective wisdom emerges when four conditions are met:
Diversity of opinion (each person has unique information),
Independence (people's opinions aren't influenced by others),
Decentralization (people can draw on local knowledge), and
Aggregation (a way to combine private judgments).
One of the most famous real world examples is Francis Galton’s Weight of an Ox. Back in 1906 at a country fair, the statistician Galton observed a contest where approximately 800 people guessed the weight of an Ox within 1% of the actual weight. What Galton discovered was that crowds of people can make surprisingly good decisions in the aggregate even when they have imperfect or unknown information.
Maybe we can revisit this example by having a giant baseball airlifted into stadiums for fans to guess the weight. Create a new tradition for Opening Day!
How do we harness this power of aggregation for the good of fantasy baseball?
By incorporating it into our player projections and their playing time.
Jeff Zimmerman, contributing analyst at RotoGraphs and co-author of The Process, has recently written two articles that continue to emphasize and support the importance of wisdom of the crowd. The articles both relate to hitter projections and playing time.
The simplest way to state Jeff’s conclusions in both articles is to aggregate. I encourage you to read through the results of the studies that Jeff set up to test, but again, an aggregate of projections and playing time leads to more predictive results (similar to the Ox example above).
There are a couple of methods to aggregate.
You could download an already established projection aggregator such as Ariel Cohen’s Average Total Cost (“ATC”) projections or FantasyPro’s Zeile projections (named for former baseball player Todd Zeile who played for 11 different teams across 16 MLB seasons).
You could use the Smart Fantasy Baseball Projection Aggregator created by Tanner Bell (co-author of The Process). Here you can control the inputs and weighting. This is my preferred preference as Tanner makes a very easy-to-use spreadsheet to provide the ability to customize.
As much as aggregation helps, you can’t just blindly rely on the average as that only gets you so far. They are always limitations to every method.
👉 Make Wisdom of the Crowd Great Again
To make aggregation a more effective tool, we need to reinforce other key components, specifically diversity of opinion and independence.
From an interview on the podcast The Knowledge Project, Philip Tetlock, a professor at the University of Pennsylvania and author of the book, “Superforecasting: The Art and Science of Prediction”, discusses how we can get better predictions beyond the average.
“We were able to beat averaging by doing some simple things like giving more weight to better forecasters as we got more and more data on who the good forecasters were, who the more intelligent forecasters were, who the more frequent belief updaters were, various attributes of forecasters. We were able to give more weight to certain forecasters and we created weighted averages. Weighted averages beat the average.”
So, it’s not just picking the right crowd, but also choosing the right individuals within the crowd. Said in another way, adding more just for the sake of adding doesn’t improve your predictions. You want to select more informed projections with a unique perspective, and weigh those more heavily.
This is the approach that Ariel Cohen’s ATC projections utilizes. ATC is not only applying aggregation but assigning weights based on historical performance to each individual projection source. The result is hopefully a more informed aggregation.
As I mentioned above, I utilize Tanner Bell’s Projection Aggregator tool, and incorporate the results of back testing and research that Jeff Zimmerman has completed over the years with his review of individual projection systems.
🚩 An important note from Jeff’s article on aggregating playing time. A significant finding was that for almost all projection systems they tended to over-project playing time for top players. This optimism bias stems from thinking that players will either bounce back or shake off injuries quickly. Jeff has suggested one option to improve playing time estimates and to adjust for these overly optimistic projections is to account more for age, previous playing time (proxy for health) and talent (projected OPS). Jeff has provided a formula for this in his and Tanner’s book “The Process”. Word of caution, the formula is not predicting the future, but providing more tempered expectations of playing time.
👉 Declaration of Crowd Independence
Another limitation of crowd wisdom is making sure it stays independent. You keep that independence by not knowing the opinion of others to eliminate social influence. If not, then crowds fall prey to these groupthink traps:
Over-projecting star players (Name value!)
Following industry consensus (Sleeper picks!)
Emotional rather than rational decisions (Highlight reels!)
Projections should help us as fantasy managers cut through these groupthink traps and stay independent in our analysis. However, we will get influenced in one way or one another in our utilization of projections. This stems from the timing of when we look at projections, and how that shapes our analysis.
Ariel Cohen ran a great poll a couple of years ago on the projection process of fantasy managers. He was trying to understand whether managers get influenced by projections versus whether managers are shaped by projections.
Are you forming your own opinion ahead of time or having your opinion formed by projection systems?
Despite projections being unbiased, they are not without blindspots as the referenced in the example above on optimistic playing time. But, you can start with projections, and work off of that to correct for blind spots as per Jeff’s method with playing time.
I prefer to be shaped by projections. Once you form your opinion, it’s hard to change. We get too anchored in our initial evaluations. Sometimes we just downright ignore when there’s conflicting information or most likely, we are 100% negative towards it.
It’s still good to question everything, and continue to look for biases in projections and other factors that could be missing.
The ultimate question you need to answer for yourself is: are you just following the crowd or using crowd wisdom?
Thanks for reading.
Take care.