Baseball's projection season is over and nothing destroys the prognostications better than actual baseball. As someone who has worked with baseball projections for a long time, the season is a six-month marathon of me looking smart and stupid, and it's impossible to keep these feelings entirely separated from rooting interests.
Since I don't put my fingers on the scale, there are always projections that I worry about more than others, whether it's disagreement or a player profile that makes a player harder to predict. Here are the players who will cause me the most sleepless nights over the next six months.
Bryce Harper, Phillies
Despite his phenomenal talent, Harper is still a player we're learning about from a performance standpoint. Harper vs. Mike Trout never became the battle of phenoms many were expecting: Trout shot to the super-mega-elite level and stayed there, and Harper put up one crazy MVP season, a few more good ones, and other seasons that were filled with disappointment and/or injury.
Who is Bryce Harper the player? We think he's a superstar, but he has yet to put together a run of superstar seasons. Projections take the middle ground and ZiPS projected a .263/.403/.546 line with 38 home runs and 106 RBIs, certainly an excellent season at 4.8 WAR but numbers that still feel watered down to what he "ought" to be doing. The Phillies aren't paying him more than $300 million to be a regular ol' All-Star.
So far, so good. Harper is off to a hot start, but what impresses me from a long-term standpoint even more than the small-sample numbers are his contact numbers. He's swinging at fewer bad pitches and more good pitches than in any season in his career. Harper's best offensive season came the year he destroyed nearly every fastball that came his way (plus-45 runs in 2015) and his worst came when he didn't (plus-7 runs in 2016). As long as he's swinging at and crushing good fastballs, I think we'll get Great Harper.
As for defense, who knows?
Shane Bieber, Indians
Looking at the top pitchers as projected by ZiPS, there wasn't much of a surprise at the top of the list. There's a bevy of Cy Young winners and near-winners, and an underrated young pitcher, German Marquez. Then at 14th in the rankings, there's a surprising name: Bieber.
When I saw his initial projection, the first thing I did was double-check the data. Yes, Bieber had nice peripherals in his rookie year (3.23 FIP), but a lot of young pitchers do that and don't get such lofty projections. I was sure ZiPS was crazy, but then again, Bieber's spring, during which he put up a 2.25 ERA and 20 strikeouts against only four walks, didn't do much to dispel the notion that I'm the one who's crazy.
So what would success for Bieber look like? I'd be watching his changeup. Primarily a fastball-slider pitcher in 2018, Bieber rarely changed speeds and even when he did, it didn't feature much of a velocity difference (only 5 mph). Bieber had large platoon splits in 2018 (around 250 points of OPS) in large part because he doesn't have a pitch to deal effectively with lefties. One of Bieber's spring tasks was working on his changeup, which he used more effectively, but if he's going to match this crazy optimism, he's going to have to use the pitch and have it be effective.
Juan Soto, Nationals
Soto is not really Harper's direct replacement since they played together in 2018, but when it comes to being the dynamo at the center of the Washington lineup, Soto is inevitably going to be compared to Harper for obvious reasons.
Soto provides a challenge for projection systems because they use history as a guide. But Soto's rise is virtually unprecedented -- he played a mere 23 games above Class A before doing damage in the major leagues. Even Trout played 161.
For teenagers with 400 plate appearances, Soto had the best OPS+ ever in 2018 at 142. Only two other teenagers even beat an OPS+ of 120: Mel Ott and Tony Conigliaro. If you add 20-year-olds to the mix, you get the following list of players who topped 130:
Ty Cobb
Mel Ott
Al Kaline
Mickey Mantle
Ted Williams
Rogers Hornsby
Jimmie Foxx
Frank Robinson
Dick Hoblitzell
Tony Conigliaro
Sherry Magee
John McGraw
That's 12 players, nine of whom are in the Hall of Fame. Conigliaro was one of the most feared phenoms in baseball until he got hit in the eye with a pitch from Jack Hamilton. Magee was on a Hall of Fame path until he declined very early in his 30s. That leaves just Hoblitzell, who faded very quickly during the dead ball era.
ZiPS is highly optimistic about Soto, predicting him to be the second-best offensive player in baseball over the next three years. That feels high to me, but who knows? We're in uncharted territory.
Clayton Kershaw, Dodgers
We haven't seen Kershaw's performance collapse yet, but his 2.73 ERA in 2018 was his worst since 2010 (2.91). Two factors have made Kershaw difficult to project: the lingering back injuries that are once again robbing him of playing time and his disappearing velocity. Though pitchers can be successful throwing 90-91 mph, the fact that it represents a sharp decline for Kershaw is a concern.
Folks making projections know about the injury and the velocity decline, but how much one leads to the other, and how much the latter will improve with good health is hard for even pitching coaches to figure out. When Kershaw is finally declared healthy enough to pitch in the majors, I'd be looking hard at that radar gun. He might be successful throwing 90 long term -- Frank Tanana famously survived an injury-related shift from being one of the hardest throwers in baseball to one of the softest -- but there's bound to be an adjustment phase. But if Kershaw is hitting 93-94 regularly, I wouldn't worry as much.
Yoan Moncada, White Sox
Moncada certainly seems like a player who should be further along in the development process than he is. ZiPS was very high on his future for a long time, ranking him as high as 18th among MLB hitters in rest-of-career projected WAR before the 2017 season. But he hasn't made as much progress as the computer expected (or the White Sox, I wager) and that number dipped to 33rd before 2018 and 76th before this season.
What's frustrating about Moncada is that he already has the hardest part of plate discipline down, being able to recognize and not swing at pitches out of the strike zone. For his career, he has swung at only 24 percent of the pitches he has seen, with 30 percent being around the league average. But he's almost average at swinging at pitches in the zone (64 percent vs. 66 percent average).
In other words, he's good at identifying pitches, but he's still not successful at actually hitting those pitches, so he has an inordinate number of swinging strikes. This is a fairly unusual profile for a strikeout hitter, who usually either swings at a high percentage of pitches and misses a lot, or is more selective and takes a lot of strikes. Moncada is neither. He's a selective swing-and-miss hitter, as weird as that sounds.
ZiPS is still projecting him to be league average (.234/.320/.406 coming into the season), but if Moncada's contact numbers ever creep up, I suspect he could get better shockingly fast. So keep an eye on those plate discipline numbers.
Luis Castillo, Reds
Who is Castillo? After he burst into the majors putting up a 3.12 ERA and nearly 10 strikeouts a game over 15 starts, the Reds thought they had a positive answer. Halfway through 2018, Castillo had a 5.49 ERA and the Reds weren't sure. Even when he was struggling, Castillo's peripherals weren't bad in 2018, but he became mistake-prone, a dangerous weakness to have in a homer-friendly ballpark like Great American.
Keep an eye on Castillo's ground ball rate; his periods of success in the majors have correlated with those periods when he's able to keep the ball down enough to avoid danger. If Castillo's ground ball-to-fly ball rate is above 1.60 or so this year, he has a real shot to be the ace the Reds have not been able to develop during their rebuilding cycle.
Rougned Odor, Rangers
Suspiciously, for a player with a brother also named Rougned Odor, Rougned Odor's monthly splits look as if they could come from two completely different players.
Since the start of the 2017 season, Odor has played 12 full months with the Rangers. In 10 of those 12 months, his OPS was either above .800 or below .650. He has had a .694 OPS over these two seasons, but his OPS in any given month rarely is around that number.
Looking at 12-month chunks throughout history, I can't find a more erratic period for a full-time hitter in my database. Odor is oscillating wildly between being a major league star and a Double-A benchwarmer. Trying to split the difference, ZiPS projects him as a .249/.307/.445 player. Projection systems try to establish baselines, but trying to pin down where Odor fits is like trying to eat soup with a fork. Maybe some month-to-month consistency would provide a foundation for Odor to grow.