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The Reds promoted Nick Senzel to the major leagues on May 3. Exactly one month ago.
Since then, the 23-year-old hitting machine from Knoxville put up a line of .267/.331/.450 with a wRC+ of 102. As a batter, he’s been a few percent better than major league average. Senzel is a fast runner and seemed comfortable and competent in center field.
Beyond the slash line and eye test, how has Nick Senzel performed in his first month as an MLB player?
Before we dive in, know this: It’s a look backward, not projection. The tiny sample size and arbitrary calendar-page endpoint make it meaningless as a predictor. A bad couple days this week could push Senzel from above to below average in several of these statistics.
That said, Senzel has 28 games in the Reds scorebook. One month as a batter, a base runner and defender. Let’s look at the record.
CONTACT SKILLS
Contact skills are basic to hitting. For success at the plate, the batter has to strike the ball often and with authority.
Contact Rates: Nick Senzel had a better-than-average overall contact rate (79.5% vs. 76% league-wide) and lower-than-average swinging strike rate (9.5% vs. 11% league-wide). His contact rate on pitches in the zone (Z-Contact%) was league average at 85%. But his contact rate on pitches outside the zone (O-Contact%) was better than average (69% vs. 62% league-wide). His strikeout rate of 27% was a bit higher than the MLB average of 23%.
Barrels: A batter can be measured based on the quality of his contact.
Statcast defines best level of contact as a Barrel. It’s a type of hit that leads to a certain minimum threshold batting average (.AVG) and isolated power (ISO). To be a Barrel, a batted ball must have an exit velocity (EV) of at least 98 mph and fall into a range of launch angles. For example, a ball with an EV of at least 100 mph and launch angle between 24-33 degrees is considered Barreled.
In his first month, Nick Senzel had 84 batted balls. 11 of them were determined to be barreled. That’s a rate of 8.5%, above league average of 6.2%.
Batted Ball Profile: A hitter’s batted ball profile (ground balls, fly ball, line drives and pop-ups) can tell us something about his quality of contact. Senzel has hit fewer ground balls than the average batter (41.7% vs. 45.6%) and more fly balls (37% vs. 22%). His line drive and pop-up rates are close to league average. He distributes his ground balls relatively evenly across the diamond.
Expected Batting Average: Senzel’s xAVG (based on the quality of balls he’s hit) was .259. That’s higher than league average (.251) but below his actual batting average (.267). So he was a little bit lucky on hits falling or his speed produced infield hits at a higher-than-normal rate.
Here’s the breakdown of Senzel’s xAVG based on batting zone:
As you can see, Senzel did better against balls high in the strike zone compared to pitches low in the zone.
Pitch Tracking: Out of the nearly 500 pitches Senzel saw, two-thirds were some variation of fastball (4-seam, 2-seam, cutter, split), a quarter was breaking balls (slider, curve) and the rest were off-speed (change).
In terms of contact, Senzel thrived against the fastball, with an xBA of .284 and actual BA of .310. Against breaking pitches, he struggled, with an xBA of .198 and actual BA of .143.
PLATE DISCIPLINE
Swing% and BB%: Nick Senzel’s swing rate was smack on league average at 46%. Senzel walked in 9% of his plate appearances, which is just above league average of 8.8%.
OSwing% The best measure of a player’s plate discipline is the rate he swings at pitches outside the strike zone (O-Swing%). Nick Senzel’s O-Swing% (22%), was considerably lower than MLB average (28%). In fact, Senzel’s O-Swing% was the second-lowest among Reds regulars, behind only Joey Votto (20.7%) and ahead of Jesse Winker (26.1%).
Senzel has been able to lay off the outside pitches, but did swing at a high percentage of inside balls off the plate. Here’s a chart for that:
First Pitch Swing: Senzel swung (35.4%) at a higher-than average (28%) rate of first pitches. That’s consistent with his relatively high swing rate (70.5%) at pitches in the zone. League average is 66%.
POWER
Home Runs and ISO: Nick Senzel had 4 home runs in 125 plate appearances. Multiply those numbers (which you shouldn’t) to get a full season of PA and you’re at 20-25 homers. That’s consistent with his home run rate at Tennessee and in the minors. His Isolated Power (ISO) was .183, above league average (.177). His Hard-Hit ball rate of 42.4% was above average of 34.3%. Eugenio Suarez leads the Reds in that category at 50%.
Pull Rate: One way for a batter to boost his power is to increase his pull percentage. Get the ball in the air and pull it. This strategy has allowed players such as Francisco Lindor and Jose Ramirez to become home run hitters. After all, the shortest distance to the bleachers is down the line. The HR/FB rate is ten times higher on the pull side than in the opposite field and four times higher than to center. Importantly, research has shown that pulling the ball is a repeatable skill that can be learned.
This is an area where Nick Senzel lagged in his first month. While Senzel’s ground balls were evenly distributed across the diamond, his fly balls had a strong tendency toward the opposite field.
Senzel’s pull-rate was only 23.5% with league average being 36.3%.
Sitting down? Nick Senzel and Derek Dietrich have hit about the same number (31-32) of fly balls. But Senzel has pulled only four, resulting in one home run. Dietrich has 18 pulls and 13 home runs on those balls. The secret to Dietrich’s home run surge? Pulling.
Exit Velocity: Senzel’s average exit velocity was 88 mph, slightly above league average of 87.4% In percentage of balls hit above 95 mph (36.6%), Senzel ranks 196 out of 331 batters with at least 50 batted balls.
Exit velocity on fly balls and line drives has a strong correlation with power metrics such as HR/FB, ISO and Hard%. Senzel’s EV on FB/LD was 92.4 mph, slightly below league average of 93.1 mph.
Expected Isolated Power: Senzel’s actual ISO was .183. His expected ISO, based on the balls he hit, was .199. That’s well above league xISO average of .158.
ISO Pitch Tracking: Senzel performed at a high level against fastballs. His actual ISO of .276 was surpassed by his xISO against fastballs of .296. But against off-speed pitches, Senzel has no extra-base hits, so an ISO of .000.
DEFENSE
DRS and UZR: Nick Senzel has played every inning in center field, a position he’d never practiced before this season. He has one error. The Defensive Runs Saved (DRS) metric has him at -3 mostly due to a negative Range grade. Ultimate Zone Rating (UZR) has Senzel at -0.9 and UZR/150 (what a player’s UZR would be over 150 games) is -10.2. Last year, the worst UZR/150 score was -24.5. A UZR/150 score of -10 means Senzel’s defense would cost the Reds 1 game this season. Senzel’s arm is rated positive by both DRS and UZR.
Outs/Catches Above Average: Senzel’s rating by Statcast Outs Above Average is -1. His expected catch percentage was 81% and actual catch percentage 79%. His weakest direction was coming in toward right field.
The chart below plots the hang time of hit balls (vertical axis) against distance the player starts from where the ball lands (horizontal axis). Red dots are outs, gray dots are hits. The green stripes in the middle represent gradually increasing levels of difficulty. The dots above the green lines are plays that should certainly be made. The dots below the line are hits that could not be caught.
For Nick Senzel, the chart shows he’s made all the plays but one that he should have made plus the 1-star and 2-star difficulty plays. The lone exception was a fly ball hit right to him that he dropped for an error. Senzel has been 50-50 on the 3-star and 4-star difficulty plays. He has yet to make a catch in the 5-star difficulty category.
Defensive Composites: Baseball-Reference rates Senzel at -0.3 dWAR. Overall, FanGraphs rates Senzel at -0.4, which is the number of runs above/below average a player is worth. The FanGraphs number includes a positive adjustment (+0.4) for Senzel playing CF. Baseball Prospectus has Senzel at -1.9 Fielding Runs Above Average.
SPEED and BASE RUNNING
Sprint Speed: Nick Senzel is fast. His sprint speed of 28.9 ft/second leads the Reds and is in the top 10% of baseball. It’s just above average for major league center fielders.
Net Stolen Bases: Nick Senzel attempted 8 stolen bases (SB) and was successful 5 times for a success rate of 62.5%. That’s below the 75% level necessary for stolen base attempts to be a net positive contribution to team run scoring. In an age where home runs generate a high percentage of runs scored, base runners and outs are far more important than extra bases.
Composite Base Running: Various sites produce composite statistics on base running that include not just stolen base attempts, but a variety of other running plays, such as taking extra bases, being thrown out, etc. The number represents the runs above or below average the player contributes through base running.
FanGraphs (BsR) has Senzel at -0.2 while Baseball Prospectus has him at -0.3. These are counting stats. The main culprits for Senzel are the low SB success rate and getting thrown out on the bases a couple of times.
HANDEDNESS SPLIT?
In his first month with the Reds, Nick Senzel showed a pronounced handedness split.
Senzel crushed LHP. He was the equivalent of a top-25 hitter against lefties. On the other hand (ha), he’s been been Tucker Barnhart against right-handed pitchers. Senzel’s strikeout rate was an astronomical 36 percent against RHP.
The handedness split exists for batting average, strikeouts, power and overall weighted average. Luck (or defense) on batted balls explains a quarter of it. But a gap of 82 points persists even with expected weighted OBA.
Another way to see this is to compare Senzel’s heat maps vs. RHP (top) and LHP (bottom).
The good news is that Nick Senzel has never exhibited this kind of split prior to the 2019 season. To the contrary, he consistently hit better against RHP compared to LHP throughout his minor league career.
Senzel’s first month handedness split is likely nothing more than an interesting artifact of a small sample.
COMPOSITE METRICS
Batting Only: Metrics that measure overall offensive batting contribution through linear weighting of outcomes show Nick Senzel was a few percent above average. The league weighted On-Base Average (wOBA) is .317. Nick Senzel’s wOBA was .331. His weighted Runs Created Plus (wRC+) was 102. The “plus” in wRC+ means the stat is scaled to a league average of 100.
WAR: Wins Above Replacement (WAR) statistics generate a composite number for the overall value of a player. It includes offense, defense and base running. Every organization has its own methodology for coming up with a single number per player. There’s no alternative to composite numbers if a front office or fan wants to compare players with any rigor.
Composites are estimates, not precision instruments. The fact that different sources come up with varying numbers is a strength not a weakness. The differences show the range based on methodology. They are counting stats, not rate stats.
The three main public data services are in agreement about Nick Senzel’s first month. FanGraphs has him at 0.4 WAR, Baseball Prospectus at 0.3 WAR and Baseball-Reference has Senzel at 0.2 WAR. That’s about as close as you’ll see.
In each case, Senzel’s solid offensive contribution is partially offset by below average base running and fielding. Senzel gets a positive positional adjustment for playing CF, a tough position.
ASSESSMENT
Again, this is a one-month report card, not a projection or prediction. That caveat in mind …
Nick Senzel performed at a high level as a hitter for a rookie in his first month in the major leagues. Underlying measures show reason for optimism regarding Senzel’s contact, on-base and power skills. The few areas where he showed a need to improve (pull hitting, off-speed pitches) are deficiencies easily explained by inexperience and initial adjustment to major league pitching.
The Reds stuck Senzel at an unfamiliar defensive position to get him in the lineup. The limited range he demonstrated last month in CF is not due to natural ability, because he’s fast and his past performance in the infield speaks to his reflexes and eye-hand coordination. More likely Senzel’s short range was a product of inexperience with various major league parks. As he becomes more confident with the position and outfields, expect his range to increase. With his documented speed and strong arm, Nick Senzel could excel at CF.
In net value for the Reds, Senzel’s base running and defensive issues largely canceled out his offense. That’s not a situation you’d expect to continue for long.
Senzel’s first month in the big leagues may not have been the literal game-changer many Reds fans had hoped for when pounding the table for his promotion. But Nick Senzel’s early performance has demonstrated plenty of promise.
