Tuma: Using THE BAT X to Find Hitter Values on Underdog Fantasy

Jan 31st 2023

Brendan Tuma

The Dinger, Underdog Fantasy's $10 Best Ball contest with $500,000 in prizes, is live. It's accompanied by The Warmup, a $3 tournament with $25,000 in prizes.

This means it's time to get serious about drafting. Throughout the month of January we covered macro-level draft topics such as:

  1. Understanding Outfield Scarcity

  2. Aces Are Undervalued

  3. Late-Round Pitchers Are a Trap

But now is a good time to start thinking about specific players to target. To do so, I ran the hitter projections provided by Derek Carty's THE BAT X through UD's scoring system. I then compared those rankings with where hitters are going in drafts to find undervalued players.

This isn't an exact science for several reasons -- positional scarcity and range of outcomes being two of them. Additionally, Underdog is a weekly game and these projections are for season-long outcomes. Still, it's early enough in draft season where there are inefficiencies to take advantage of. I chose to write about 3 of the hitters who stuck out to me the most.

To view my rankings for Underdog, click here. Message me on Twitter, @toomuchtuma, if you need help uploading the rankings into UD to use while drafting.

Alex Bregman, IF, Astros

Bregman is the earliest hitter going in drafts where there's a meaningful difference between his Underdog ADP and his projection according to THE BAT X.

Presently, Bregman is the 36th hitter off draft boards despite having the 22nd best hitter projection for UD scoring.

This is partly due to outfielders being pushed up draft boards. Byron Buxton and Adolis Garcia go immediately before him while options such as Randy Arozarena, Cedric Mullins, and Luis Robert are consistently taken 10-20 picks earlier.

Personally, I wouldn't pass up Bregman's raw scoring just to take a player at a weaker position. To me the outfield dilemma can be solved by taking one in Round 1 (assuming you aren't picking at the turn) and then skipping over this early "OF dead zone" to take advantage of someone like Bregman who keeps getting passed over.

Game theory aside, Bregman's skill set is perfectly suited for Underdog scoring. Whereas his 5x5 roto lines leave something to be desired for managers playing in those formats, Underdog more greatly rewards walks and doubles.

Using THE BAT X's projections, just three players combine for more walks+doubles than Bregman - Aaron Judge, Juan Soto, and Mike Trout, and they all go inside the first 7 picks of drafts.

Bregman's season-long projection using THE BAT X adds up to 1,353 points on UD, more than Marcus Semien (1,288) and Bobby Witt Jr. (1,273). Bregman can be had 10 picks later than Semien and 20 after Witt.

Matt Chapman, IF, Blue Jays

As striking of a value as Bregman appears to be early in drafts, Chapman presents an even higher delta between his THE BAT X projection (27th among hitters) and his UD ADP (86th!!).

Chapman is a career .240 hitter to go along with a .329 OBP. That doesn't seem like anything special, but his low batting average disguises the fact that he had an 84th percentile walk rate in 2022 (91st percentile in 2021).

His OBPs aren't a difference maker for managed leagues that use the stat because his batting average is dragging it down by so much, but he still walks a lot. In fact, THE BAT X projects him for 70 walks in '23, the 17th highest total among hitters. He had 68 and 80 walks the past two years, respectively.

Chapman also projects for 32 homers, the 14th highest total according to Carty's system. In his case, correctly valuing homers and walks are all it takes to be a screaming value in current drafts.

Nick Castellanos, OF, Phillies

Castellanos is the 60th ranked hitter according to THE BAT X's projections and he's the 60th hitter going in UD drafts. Efficient, right?

I think he sticks out for two reasons, though. First, he's a classic bounce back bet coming off a down season. Castellanos hit just .263/.305/.389 (94 wRC+) in his first year with the Phillies.

Castellanos was one of the players to sign after the lockout, during a modified spring training and the frantic buildup to Opening Day. After the season he commented on relating to a Kris Bryant quote about his entire season feeling rushed. He noted that after the lockout it became about hurrying to find a team, get to spring training, and figuring out where to live.

Castellanos also had a kid this season and had to become the everyday right fielder once Bryce Harper transitioned to being a full-time DH. Other late signees like Bryant and Trevor Story didn't have smooth transitions either. Yes these players made more money this year than most of us will ever see in our lives, so it's easy to have an attitude of "so what", but I'm at least willing to entertain the idea he'll be more comfortable in Year 2.

Soft sciences aside, the math also backs up Castellanos as a value. While he's currently 60th in both projection and ADP, it's important to point out he's an outfielder. When I ran through all the hitter projections and ADPs, nearly all of the "values" were infielders.

This makes sense since drafters are pushing them down the board due to the surplus. Therefore, an outfielder projecting as a "push" is actually a value and Castellanos is one of the only players in the middle rounds to fit this description.