The fantasy baseball ranking season is in full swing. For me, that typically starts with searching advanced stats leaderboards. Advanced statistics are often more predictive than traditional box score statistics. Thus, they’re an excellent jumping-off point. This series will dive into a variety of my favorite advanced metrics. However, I must caution that no statistic in isolation is the secret sauce for unearthing a hidden gem or burgeoning stud. Instead, they are a piece of the puzzle and best viewed through that lens, using other statistics in conjunction with them to formulate a well-rounded opinion of the fantasy value of players.
Dominate with our award-winning fantasy baseball draft software 
Zone-Swing Percentage (Z-Swing%)
Zone-Swing percentage (Z-Swing%) measures swings at pitches inside the strike zone divided by total pitches inside the zone. In isolation, it’s not an especially useful stat for fantasy baseball analysis. However, when used with other statistics, it can be handy.
For instance, a high Z-Swing% might be representative of a free-swinging hitter. However, if the player in question has a low O-Swing% and a high Z-Swing%, it indicates the hitter has a superb handle on the strike zone, laying off pitches out of the zone and attacking pitches in the strike zone. Thus, the Z-Swing% leaderboard is filled with a wide variety of hitter archetypes.
Additionally, a high Z-Swing% is a path for hitters with contact issues to cut down their strikeout rate. Expanding on that idea, by taking more bites of the apple with swings at pitches in the strike zone, a player with a poor SwStr% has multiple chances to make contact and put the ball in play.
According to FanGraphs, the league average for Z-Swing% in 2021 was 68.9%. Further, among 132 qualified hitters, the highest Z-Swing% was 83.4%, and the lowest mark was 58.2%. Fortunately, a low Z-Swing% doesn’t preclude a hitter from being valuable offensively. Hitters with excellent bat-to-ball skills can take pitches in the strike zone without racking up a high strikeout rate. But, again, Z-Swing% requires additional context to paint a clearer picture and have utility for fantasy baseball analysis.
2021 Qualified Hitters Z-Swing% Leaders
There are many fantasy baseball studs and high-end contributors on the above leaderboard, including Ozzie Albies (2B - ATL), Kyle Tucker (OF - HOU), Tim Anderson (SS - CWS), Bo Bichette (SS - TOR), Freddie Freeman (1B - FA), Fernando Tatis Jr. (SS/OF - SD), J.D. Martinez (OF - BOS), Rafael Devers (3B - BOS), and more. However, as that list of players showcases, there are very different hitter profiles among the Z-Swing% leaders.
For example, Tucker, Freeman, and Bryan Reynolds (OF - PIT) have a lower than average O-Swing%. Conversely, among qualified hitters, Salvador Perez (C - KC) had the highest O-Swing% (48.3%), and Javier Baez (SS/2B - DET) (46.6%), Bichette (42.5%), Avisail Garcia (OF - MIL) (41.8%), Ryan Mountcastle (1B/LF - BAL) (41.5%), Anderson (40.5%), Nick Castellanos (OF - FA) (40.4%), Josh Harrison (UTL - FA) (38.9%), and Albies (38.5%) were inside the top-15 in highest O-Swing% at third, fourth, fifth, sixth, seventh, eighth, 11th, and 13th-highest, respectively.
Expectedly, the vastly different styles of hitter on the leaderboard led to a wide span of strikeout rates, ranging from Baez's 33.6 K% down to Harrison's 13.4 K%, with a 22.3 K% as the median -- measured by averaging Trevor Story's (SS - FA) 23.4 K% and Kris Bryant's (3B/OF - FA) 23.0 K%. Still, the aggressive Z-Swing rates helped suppress the strikeout rates of full-blown free-swingers Anderson (21.6 K%), Castellanos (20.7 K%), Bichette (19.9 K%), and Albies (18.7 K%). So, remember, a high Z-Swing rate is a way hitters can attempt to whittle down their strikeout rate. Unfortunately, there's a limit to how much it can help, evidenced by Baez's 33.6 K%.
Noteworthy Non-Qualified Hitters in 2021
Corey Seager (SS - TEX) has found a happy balance between working walks, avoiding overextending his zone (32.0 O-Swing% versus a league average of 31.3%), and ripping the ball with authority. As a result, he is a great bet to help in batting average.
Luis Robert (OF - CWS) and Byron Buxton (CF - MIN) are a pair of toolsy outfielders that can put a charge into the ball. However, they had a 16.2 SwStr% and 14.8 SwStr% in 2021, and the league average was 11.2%. Thankfully, their aggressive approaches on balls in the strike zone allowed them to do damage at the dish, keeping their strikeout rates in check. According to FanGraphs, the league average strikeout rate in 2021 was 23.2%. Meanwhile, Buxton had a palatable 24.4 K%, and Robert had a 20.6 K%.
- Advanced Stats Leaderboard: Starting Pitchers CStr%
- Advanced Stats Leaderboard: Starting Pitchers CSW%
- Advanced Stats Leaderboard: Starting Pitchers O-Swing%
- Advanced Stats Leaderboard: Starting Pitchers GB%
- Advanced Stats Leaderboard: Starting Pitchers SwStr%
- Advanced Stats Leaderboard: Starting Pitchers Soft%
- Advanced Stats Leaderboard: Starting Pitchers IFFB%
- Advanced Stats Leaderboard: Starting Pitchers Z-Contact%
- Advanced Stats Leaderboard: Starting Pitchers BABIP
- Advanced Stats Leaderboard: Hitters BB/K
- Advanced Stats Leaderboard: Hitters FB/LD Exit Velocity
- Advanced Stats Leaderboard: Hitters Barrel%
- Advanced Stats Leaderboard: Hitters Z-Contact%
Complete a mock draft in minutes with our free Draft Simulator
Subscribe: Apple Podcasts | Spotify | Google Podcasts | Stitcher | SoundCloud | iHeartRadio
Beyond our fantasy baseball content, be sure to check out our award-winning slate of Fantasy Baseball Tools as you prepare for your draft this season. From our free mock Draft Simulator - which allows you to mock draft against realistic opponents - to our Draft Assistant - that optimizes your picks with expert advice - we've got you covered this fantasy baseball draft season.
Josh Shepardson is a featured writer at FantasyPros. For more from Josh, check out his archive and follow him @BChad50.
