Fantasy Freestyle: Risers and Fallers in OBP Leagues

More and more fantasy team owners are playing in otherwise standard 5×5 AL-only and NL-only rotisserie leagues that replace AVG with OBP. It makes sense from a sabermetric standpoint if the goal of the league is to capture actual offensive value since OBP is a better measure of a player’s contributions than AVG. However, since OBP isn’t standard, a lot of expert guides set their bid limits using the more frequently used AVG. I used the Baseball Prospectus Player Forecast Manager (PFM) to see which players PECOTA thinks have the biggest swings in valuation in standard 5×5 AL-only and NL-only roto leagues.

While configuring the PFM for this exercise, I used a standard AL-only or NL-only auction-style rotisserie setup (14 hitters, nine pitchers, $260 budget, 70/30 hitter/pitcher split). I changed only the League Used dropdown and the AVG and OBP checkboxes between runs. If you’re trying to play along at home, here are the rest of the PFM configuration settings I used:

Lastly, here’s a guide to the numeric fields that will appear in the tables in each of the four sections below:

OBP $ – the player’s PFM valuation in a 5×5 AL-only or NL-only auction style rotisserie league that uses OBP as a category instead of AVG

AVG $ – the player’s PFM valuation in a 5×5 AL-only or NL-only auction style rotisserie league that uses AVG as a category

DIFF $ – the difference between the player’s value in OBP leagues and their value in AVG leagues, calculated by subtracting AVG $ from OBP $

American League – Biggest Risers in OBP Leagues
Here are the 10 players who gain the most value according to the PFM when swapping OBP in for AVG in otherwise standard AL-only leagues:

Table 1: Top 10 AL-Only Risers in OBP Leagues

PLAYER	OBP	AVG	DIFF
Bautista, Jose	$34.0	$27.3	$6.7
Santana, Carlos	$25.0	$18.5	$6.5
Napoli, Mike	$20.8	$16.7	$4.1
Choo, Shin-Soo	$18.4	$14.5	$3.9
Trout, Mike	$36.6	$32.8	$3.8
Iannetta, Chris	$10.4	$6.6	$3.8
Fielder, Prince	$22.9	$19.6	$3.4
Springer, George	$27.4	$24.2	$3.3
Sano, Miguel	$24.0	$20.7	$3.2
Encarnacion, Edwin	$28.7	$25.9	$2.8

The top 10 gainers in AL-only OBP leagues are a ringing endorsement for categorizing plate discipline as an old-player skill since seven of the ten players are 30 or older. Toronto, Cleveland, and Texas each managed to put two players in the top ten alongside players from Anaheim (guess who), Seattle, Houston, and Minnesota.

The biggest gainers from the switch from AVG to OBP gained more than $6, but by the back end of the top ten, the gain was less than $3. Unless you’re dealing with the extreme outliers in terms of walk rate, don’t bump your bid limits up more than a few dollars for players with good walk rates when adjusting for OBP leagues.

American League – Biggest Fallers in OBP Leagues
Here are the 10 players who lose the most value according to the PFM when swapping OBP in for AVG in otherwise standard AL-only leagues:

Table 2: Top 10 AL-Only Fallers in OBP Leagues

PLAYER	OBP $	AVG $	DIFF $
Escobar, Alcides	$12.7	$16.2	$3.6
Altuve, Jose	$27.6	$31.0	$3.5
Perez, Salvador	$11.2	$14.6	$3.4
Jones, Adam	$23.1	$26.3	$3.2
Rosario, Eddie	$10.7	$13.8	$3.1
Marte, Ketel	$10.0	$13.1	$3.1
Pillar, Kevin	$13.6	$16.2	$2.6
Infante, Omar	$4.4	$6.9	$2.6
Cron, C.J.	$12.7	$15.1	$2.4
Schoop, Jonathan	$9.2	$11.5	$2.3

As expected, this list includes a lot of free swingers. Unlike the list of biggest gainers, nobody on this list has a swing of more than $4, and the spread between the top and bottom of this list is much more narrow. Don’t go knocking more than that off anyone’s bid limit just because they’re unrepentant hackers.

National League – Biggest Risers in OBP Leagues
Here are the 10 players who gain the most value according to the PFM when swapping OBP in for AVG in otherwise standard NL-only leagues:

Table 3: Top 10 NL-Only Risers in OBP Leagues

PLAYER	OBP $	AVG $	DIFF $
Votto, Joey	$32.0	$25.5	$6.5
Pederson, Joc	$29.2	$23.6	$5.6
Granderson, Curtis	$24.0	$20.0	$4.0
Duda, Lucas	$19.8	$16.2	$3.6
Schwarber, Kyle	$25.9	$22.5	$3.5
Grandal, Yasmani	$15.4	$12.1	$3.3
Goldschmidt, Paul	$35.2	$31.9	$3.3
Bryant, Kris	$30.7	$27.6	$3.1
Fowler, Dexter	$20.1	$17.0	$3.1
Carter, Chris	$19.3	$16.2	$3.1

The least surprising revelation in this article is that Joey Votto tops this list. If Kevin Youkilis is the Greek God of Walks, Votto is the Canadian analogue. PECOTA’s favorite team for 2016, the Chicago Cubs, put three players in the top ten alongside two players from Los Angeles and two from New York. Like the top gainers in the AL, the increase in value is around $6.50 at the top of the list but quickly falls to around $3.

National League – Biggest Fallers in OBP Leagues
Here are the 10 players who lose the most value according to the PFM when swapping OBP in for AVG in otherwise standard NL-only leagues:

Table 4: Top 10 NL-Only Fallers in OBP Leagues

PLAYER	OBP $	AVG $	DIFF $
Revere, Ben	$19.2	$23.1	$3.9
Gordon, Dee	$25.3	$28.6	$3.3
Harrison, Josh	$18.1	$21.3	$3.2
Gennett, Scooter	$13.9	$17.0	$3.1
Murphy, Daniel	$15.0	$17.8	$2.8
Segura, Jean	$17.0	$19.8	$2.8
LeMahieu, DJ	$14.4	$17.1	$2.7
Arenado, Nolan	$21.1	$23.7	$2.6
Ramirez, Alexei	$11.5	$13.8	$2.4
Aybar, Erick	$13.1	$15.4	$2.4

Speed guys dominate this list. PECOTA projects double-digit stolen bases for eight of the 10 players shown, while the list of top 10 fallers in the AL in OBP leagues included only five players projected for double-digit stolen bases by PECOTA. Like the AL-only list, the spread between the first-place faller and the 10^th-place faller was narrower than the spread in the list of biggest gainers.

Conclusions
It looks like roto players in standard AL-only or NL-only auction-style leagues that use OBP instead of AVG shouldn’t add or subtract more than $3-$4 to their bid limits to account for the switch. Players with extremely high walk rates can gain a little more than players with extremely low walk rates will lose, presumably because the lower bound on the number of times a player can walk in a season is more binding than the upper bound. If your bid limits for AL-only or NL-only leagues that use OBP look radically different than your bid limits for AL-only or NL-only leagues that use AVG, you’ve probably over-adjusted for the change.