Estimating Weekly FAAB: Step One

A couple weekends ago, Dave Appelman asked my fellow writers and me what features we’d like to see available at RotoGraphs (more additions are in the works) and a FAAB (free agent acquisition budget) bid estimator was discussed. With so many leagues and so many bidding setups, I accepted the daunting challenge. I’m beginning to produce some limited usable results.

Before I go into the many inputs in FAAB bids such as declining budgets and absentee owners, I needed:

1. A way to measure owner seniment before the normal Sunday FAAB bids.

2. A reliable source of FAAB bids.

For the first source, I’d like to thank fellow RotoGraphs contributor, Al Melchior for pointing out that CBS Sportsline displays historic weekly ownership rates. Every host website will display ownership rates. What was important with this source is they have a ton of quick grab waiver wire leagues. As soon as a player bursts on the scene, owners can go pick them up off the wire. The ownership rates for these hot commodities immediately begin ticking up. These values are available but the bases need rounding a few times to collect them.

First, an owner needs to set up a CBS league. I can’t seem to find a way around this requirement. If anyone does, let me know. Next hover over the “PLAYERS” tab and select “STATS”. Then search by the player’s name and right click on it. This popup will appear.

From this window select the “FANTASY TRENDS” tab where the weekly ownership rates are shown.

With the help from CBS Sportsline’s Heath Cummings, I determined the ownership rates lock right before FAAB runs that midnight. It’s a perfect source of ownership rates even though they are little tough to acquire.

As for the FAAB bids, I’m going to owners who have thousands of dollars on the line and am using NFBC’s Main event bids. Thanks to NFBC’s Greg Ambrosius for letting us use the bids. The winning bids are from 34 leagues with 15 owners in each league with thousands paid in entry fees. These owners are trying to win.

The NFBC message board contains all of the weeks’ bids ($1000 budget) which can be matched up with the trends on CBS.


I decided to start my analysis with just week 14’s bids. I had no idea what useful information I was going to be able to find. And if I did find anything, I might as well make it useful during the current time frame.

I collected the average and median winning FAAB, the standard deviation in FAAB, the ownership change amount, and overall ownership rate. One item I found was that the largest bids were for single players dropped my other owners (e.g. Mark Trumbo). It was a tough call between using the single large values and those bid on the most. I went for a middle ground. I collected information on a few dozen players.

I quickly found the players needed to be divided up into two groups, possible closers (higher than average bids) and everyone else.

I tried several combinations and in the end, I found comparing FAAB bid to ‘ownership percentage’ plus ‘weekly percentage jump increase’ made a great starting point. I might need to weight each value in the future.

It is just a starting point and I may need to split the data into more groups (e.g. rookies, starters, etc) and refine the equations. What I was able to find were a couple of equations to estimate week-14 FAAB values.

Potential closers: $60.3*(Total ownership + ownership increase) + $8.4
R-squared: 0.53

Everyone else: $9.1*EXP(2.12* (Total ownership + ownership increase))
R-squared: 0.52

In each instance, I compared the standard deviation to the actual bid to find the normal range of outcomes. In each instance, the range was +/- (0.6 * expected FAAB value).

For an example, this week Enrique Hernandez, who is playing better, saw his CBS ownership jumped from 7% to 33%. So, the constant used with the above formula would be 59% (33% + (33% – 7%)).

$9.1*EXP(2.12* (.59)) = $32

Additionally, the winning bid range was projected between $13 and $51. In nine bids, he went for a little less for an average $26 bid. All but one value was in the $13 to $48 range.

Overall, it’s an encouraging start. That’s it though. It’s not useful to AL or NL only. Yet. Or smaller or deeper leagues. What it has done is encourage me to take another step and begin to refine the formula some more.

I plan on just increasing the bid sample size over the next few days. In the meantime, please let me know if there is any additions or changes I could do. I’ll be back in a day or so with some more information.

Jeff, one of the authors of the fantasy baseball guide,The Process, writes for RotoGraphs, The Hardball Times, Rotowire, Baseball America, and BaseballHQ. He has been nominated for two SABR Analytics Research Award for Contemporary Analysis and won it in 2013 in tandem with Bill Petti. He has won four FSWA Awards including on for his Mining the News series. He's won Tout Wars three times, LABR twice, and got his first NFBC Main Event win in 2021. Follow him on Twitter @jeffwzimmerman.

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5 years ago


I might have missed it, but did you check your equations across various weeks yet? I would guess that generally declining FAAB budgets might have an effect on how FAs are assessed. It wouldn’t suprise me, even, to find out that certain positions might gain or lose value at different points in the season.

After playing for a million years in non-bid leagues, I’m in my first ever FAAB league this season. I find trying to guess how other owners are going to value pickups to be maddening…

5 years ago
Reply to  Jeff Zimmerman

*lol* I did. Basically I’m asking for unfounded speculation based on incomplete research that you may or may not have already begun 🙂