Fantasy Baseball: 3 Things We Learned in Spring Training

Baseball fans love their stats. We devour them, dissect them, and build our fantasy rosters around them. Each week of 2021 baseball season, we will be gifted with another statistical sample size of pitches, plate appearances, and playing time. Knowing it often takes hundreds or even thousands of pitches or batted-ball events for trends to normalize, how should fantasy managers adjust to the ebbs and flows of weekly player performance?

Each week during this season, this piece will look at trends that have emerged over the past week and determine if it is signal or noise moving forward. What is prescriptive in helping build winning fantasy teams and what can be ignored as small sample size? Hopefully, we can make sense of what has just happened to help us make smarter roster and free agent budget decisions.

First up are three trends from what seemed like an eternal Spring Training.

The Ball, It Is Dead

Leading up to Spring Training, there were some pretty loud whispers that MLB would be deadening the baseball in 2021, a sharp turn away from 2019 when a player like Eugenio Suarez somehow belted 49 home runs. In February, those rumors were confirmed when a report surfaced where MLB essentially admitted to the balls being depressed for the upcoming season. One question answered, however, led to many other questions. Specifically, how will a deadened ball affect batted ball events and run production in 2021?

The report cited in The Athletic looked at a similar change in the Korean Baseball Organization and found that slugging percentage dropped by 14% and home runs were reduced by a third. The Korean baseball was also enlarged, so it had drastic effects, but it's safe to say there will be some correlating positive effects for pitchers and negative effects for hitters in MLB.

The truth is, we are already starting to see the effect over the last five weeks. According to ESPN, spring games are averaging 9.4 runs per game through Sunday, the lowest since at least 2015. There have also been only 1.11 home runs per game, the lowest mark since 2017. Digging deeper into data between 2019 and 2021 for Spring Training, we see some striking differences on offense.

When the rubber hits the road on the season, will we see these types of gaps between offense in 2019 and offense in 2021? Perhaps. But it's clear we should begin to temper expectations on what our elite hitters will look like this year.

Bobby Dalbec and Ke'Bryan Hayes Would Like Your Attention

There were perhaps no more dominant young hitters in all of Spring Training than Bobby Dalbec and Ke'Bryan Hayes. Look at any spring stat leaderboards and you will see their names littered across many of the categories:

Hayes is the odds-on favorite to be the National League Rookie of the year, and while Dalbec certainly has some stiff competition in Randy Arozarena, Andrew Vaughn, and potentially Jarred Kelenic, he is without a doubt in the conversation.

Both players are universally drafted in fantasy leagues this year, although at wildly different spots. Hayes checks in at 133 overall, according to FantasyPros' average draft position (ADP) data, while Dalbec falls all the way to 257.

With both players expected to do big things this season, why the massive discrepancy in draft capital? Hayes is at a scarcer position (third base), but that doesn't account for 125 spots of ADP.

Both players smashed their auditions in a small sample in their 2020 showcase. Below are their respective slugging percentages during the time they spent in the Majors last season, courtesy of FanGraphs.

Relative to average slugging percentage by age, they both crushed the ball, and expectations are high that they will repeat those figures again. But there is one clear number that separates these two and drives up the price on Hayes and has fantasy managers pumping the brakes on Dalbec: strikeout rate.

In their most recent sample, we see on the surface what could be Dalbec's downfall this year. In his 53 plate appearances this spring, Dalbec struck out at astounding 21 times (40%), while Hayes only whiffed five times in 54 plate appearances (9.3%). Below we see strikeout rate in 2020, again compared to the MLB average for their age.

Dalbec is assuredly going to hit plenty of bombs this year. Only two players in Spring Training hit more. But there are going to be some massive slumps in store for him this season if he cannot cut down on the strikeout rate and bring it below 30%. That risk was baked into his draft position, but rotisserie and points-league players should be prepared that the trade-off for potentially 35 cheap home runs might be prolonged slumps or even worse.

The Pittsburgh Pirates are going to roll out Hayes every day no matter what, but beware the dreaded "work on his swing" demotion for Dalbec if pitchers keep missing his bat.

Our projections slot Hayes in as the 72nd-best hitter this season, with a .290 average, 16 home runs, and an .836 OPS, while Dalbec comes in ranked 106th with a .249 average, 22 home runs, and just a .799 OPS.

The Six-Man Rotation Revolution is Here

According to the starting pitcher depth charts page on FanGraphs, only 18 of 30 teams project to have five pitchers throw at least 100 innings this year. Some of that is a component of injuries, but in most cases, it reflects an emerging trend across Major League Baseball: the era of the six-man rotation is upon us.

Teams such as the Mariners, Tigers, Rangers, Red Sox, and Cubs are all toying with the idea openly, with the Mariners and Tigers already declaring it is their intention for the upcoming season. How does this affect our seasonal fantasy teams? On the surface, it may not seem like it will. Unless you are in the deepest of AL-Only leagues, you likely aren't drafting back-end pitchers like Chris Flexen, Nick Margevicius, Jose Urena, and Michael Fulmer anyway.

But raise your hand if you have shares of Marco Gonzales (my hand's raised), Matt Boyd, or Justus Sheffield. These pitchers could be negatively affected depending on how the schedule works out and how rigid these teams are at sticking to the six-man rotation when there are off days on the schedule. Assuming a roughly 175-day schedule, that's potentially 35 starts for your top two starters in a five-man rotation, but only 29-30 for those pitchers in a six-man schedule. If you are looking for counting stats in a rotisserie format or need those precious innings in a points league, you will have to start looking elsewhere on your roster to fill them.

If more respectable pitching staffs like the Cubs or Padres take this approach -- and there are rumors out there -- imagine what that does to top-end starters like Kyle Hendricks or Yu Darvish. Never has it been more clear that these teams care not for your fantasy squad. They are interested in preserving their most valuable arm assets for long postseason runs.

The corollary to this, of course, is perhaps the extra day of rest does our stud pitchers some good, and their performances give us higher production. What we lack in quantity we make up for in quality, as it were. A study at FanGraphs found that for each additional day of rest beyond the typical four, pitchers gained an xFIP (expected fielding independent pitching) boost of only 0.06 points. That number did not end up being statistically significant, so in the end the extra days didn't make any impactful difference on typical performance.

You likely have already drafted your pitchers for the 2021 season, but just tread carefully with these teams that plan to roll out six starters. Be prepared to have additional options if you need to make up some of the fantasy categories.