How ABS Implementation Will Change Offensive Player Valuation

Why Swing Decisions and Contact Ability Will Be Increasingly Valued

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For much of the past decade, offensive player valuation across Major League Baseball has increasingly accepted an "all-or-nothing" ideology in which elevated strikeout rates are tolerated in exchange for power production. As long as a hitter could generate damage on contact, swing-and-miss and aggressive chase tendencies were often viewed as acceptable tradeoffs rather than inefficiencies. The gradual adoption of the Automated Ball-Strike (ABS) system has the potential to completely change this approach. By standardizing strike calling and removing much of the variability at the margins of the zone, though not all yet, ABS shifts offensive value toward hitters who control the strike zone through disciplined swing decisions and consistent contact, while exposing the downside risk of profiles reliant on extreme outcomes.

Shadow Zone Problem

Under traditional umpire-called systems, the effective strike zone has historically been wider than the rulebook definition. Since 2021, there has been a trend of umpires improving with respect to pitches thrown in the "Shadow Zone," identified as the marginal areas at the edges of the strike zone seen below.

In 2021, 47.86% of all taken pitches in the Shadow Zone were called strikes. In 2024, this dropped to 46.37%. In 2025, the best year on record, this dropped further to 42.14%. Even with the 4% improvement year over year and the best season on record, over 42% of all takes were still called incorrectly. These marginal calls often extended plate appearances and placed hitters behind in counts on pitches that were not truly strikes. With ABS reducing these incorrect calls, hitters will face fewer artificial strikes early in counts and more opportunities to work into favorable situations. As a result, plate appearances will increasingly be decided by whether a hitter can correctly identify which pitches to swing at and, when swinging at pitches in the zone, whether he can put the bat on the ball.

Importance of Swing Decisions

Swing-decision metrics such as chase rate have proven to be among the most stable offensive indicators year over year and will increasingly become more heavily relied upon. In the 2025 season, the league-average chase rate was 28.2%, while there were 8 hitters who chased fewer than 20% of pitches out of the zone and 49 hitters who chased fewer than 25%. Juan Soto led the way by a large margin of over a full percentage point at 15.9% chase rate. Top-of-the-market free agent Kyle Tucker finished 4th at 17.6%.

Hitters who chase less tend to be more consistent, and though they don't often stand out in traditional power metrics, they produce value even when their raw power output might lag slightly behind more aggressive profiles. Conversely, hitters with chase rates north of 30% and elevated in-zone whiff rates routinely post higher whiff and strikeout rates, placing significant pressure on their power production to sustain overall value. In an ABS environment, the margin for error for these hitters narrows as fewer plate appearances will be extended by zone variability. Those who are able to lay off pitches outside the zone will benefit from forcing pitchers into the zone, getting better pitches to hit, and generating better quality of contact.

Contact Ability 

Contact ability further separates these profiles under a more standardized strike zone. The ability to make contact when swinging, especially in the zone, is vital. Hitters with high in zone-contact rates are far less sensitive to changes in strike calling because their offensive approach already assumes a narrow, objective zone. When pitchers are forced to throw true strikes more frequently, these hitters are better equipped to convert those pitches into balls in play rather than swings and misses. In contrast, extreme power hitters with low contact rates and high in-zone swing and miss often fail to produce quality at-bats without power production. They miss key advantages of having more pitches thrown in the zone

Winners and Losers

The implications for front offices extend beyond individual player evaluation and into roster construction and risk management. Hitters whose value is driven by swing decisions and contact quality tend to provide more consistent offensive floors across environments, rule changes, and aging curves

Steven Kwan fits perfectly into this profile. In 2025, Kwan had just an 8.7% strikeout percentage, swung and missed at just 3.9% of pitches in the zone, chased at 22.7%, and had just an 8.7% whiff rate. As a result of his extreme plate discipline and contact ability, his squared-up percentage was in the 99th percentile and xBA was in the 86th percentile, even though his xSLG and xwOBA were below league average as a result of hitting just 11 home runs. This type of profile is less volatile to outside factors such as opposing pitcher, umpire zone, weather, and more. These players are more consistent, you know what you're going to get, and they have a pretty high floor, though likely a lower ceiling, which makes them more reliable and dependable in the long term.

Power-first profiles, while still valuable, carry increased downside risk when their success depends on accepting large volumes of non-productive plate appearances. Rafael Devers exemplifies this. Devers finished 2025 with 35 home runs and an xwOBA, barrel percentage, and hard-hit rate in the 90th percentile or better. He also finished in the 84th percentile in xSLG. However, he struck out 26.3% of the time and whiffed 31.6%, which was in the 17th and 10th percentile respectively. He also had the absolute worst in-zone swing-and-miss percentage among qualified hitters by over 3% at 28.6%. As ABS reduces the tolerance for chase and swing-and-miss, teams may need to recalibrate how they price these risks in extensions, free-agent contracts, and trade valuations.

Two other players worth highlighting when it comes to who teams might value more or less are Geraldo Perdomo and Eugenio Suarez.

Perdomo is a hitter I expect to be more highly valued as a result of ABS implementation. In 2025, Perdomo ranked 7th best among qualified hitters in both chase rate and in-zone swing-and-miss percentage. Despite hitting just 20 home runs, still a career best, his elite plate discipline translated to finishing 4th in the NL in both hits and walks, 7th in RBIs, and in the top 10% of MLB hitters in xBA, wOBA, K%, and BB%. His ability to eliminate chase and consistently put the bat on quality pitches will only become more valuable as ABS is implemented.

Conversely, I expect players like Suarez to be less valued moving forward. In 2025, Suarez hit 49 home runs with 118 RBIs, a .526 slugging percentage, and .298 ISO. However, he ranked in the bottom 3% in xBA even with the fact that he was in the 89th percentile in barrel percentage. He also finished in the bottom 5% in K% and had an extremely high 31% chase rate. ABS reinforces the importance of smart swing decisions and quality of contact. It doesn't completely eliminate incorrect calls on the borders, but it certainly minimizes them

Going Forward

Ultimately, the adoption of ABS accelerates a broader shift in offensive valuation that has already begun to emerge. While home runs will always carry premium value, the ability to consistently win plate appearances through disciplined swing decisions and quality contact on strikes becomes more central in a standardized strike-calling environment. For baseball operations departments, the opportunity lies in identifying hitters whose offensive profiles are built to thrive under objective strike zones rather than exploit their inconsistencies.

Players who are more reliable will now increase in value as those who are more volatile will see their value decline. As the league continues to move away from subjective strike calling, hitters who minimize chase, limit swing-and-miss, and generate repeatable quality at-bats are likely to regain relative value, signaling a gradual move away from the most extreme all-or-nothing offensive models.