Breaking Down Isaac Collins’s Defensive Regression

Last season, Isaac Collins was an average fielder with 0 fielding run value (FRV) and grading in the 56th percentile. This season, Collins already sits at -3 FRV and is at the bottom of the rankings. What has changed?

Below is a chart showing Collins’s percentile ranks in key defensive metrics: range, sprint speed, arm strength (not yet qualified in 2026), and arm value. 

While Collins’s sprint speed has actually increased since last year, rising from 27.7 to 28.3 feet per second, his range has dropped significantly. Last season, Collins was worth +4 outs above average (OAA). This season, however, he is already at -3 OAA. This decline in range is the primary driver of his drop in FRV.

When breaking down his range, Collins has had a particularly difficult time when he has to move laterally towards the third-base side, where all of his negative OAA has come from. In his nine attempts moving that direction laterally, he has seen a success rate of only 44% compared to an estimated rate of 77%.

Collins did have back/left side tightness that delayed his start to spring training, which may be contributing to these lateral movement issues.

What’s Driving the Decline?

In terms of positioning, Collins has not been used out of the ordinary. According to Statcast, all 30 of Collins’s fielding attempts have been classified as “straight up” rather than being positioned toward the gap or foul line. However, his positioning has been shallower in left field with the Royals compared to his time in Milwaukee. The view below highlights his average position with the Royals in red, and his previous two years with the Royals in green.

Collins had an average depth of 289 feet in 2026 with the Royals, compared to an average depth of 306 feet last season with the Brewers. Even after moving in the fences, Kauffman Stadium has a deeper left-center field (379 ft) than American Family Field in Milwaukee (371 ft).

Despite him playing shallower, he is performing as expected in four attempts, going back with a success rate of 75% versus an estimated success rate of 74%. If his positioning is not noticeably contributing to his value, where else could the problem be? 

Jump and Route Efficiency

In 2026, Isaac Collins ranks 33rd out of 46 qualified outfielders in overall jump. His initial reaction is good, ranking third with 3.5 feet covered above average in the first 1.5 seconds. His burst is closer to average, with 0.3 feet covered above MLB average in the 1.5-second burst after the initial reaction.

The issue lies with his routes. Collins ranks last in route with 4.8 fewer feet covered against the direct, optimal path, over a foot worse than the second-worst outfielder.

Even though his reaction and burst times are good, his inefficient routes to the ball make him below average for overall outfield jump, with 0.9 fewer feet covered than average. Considering that he is starting on average 17 feet closer to the infield for his positioning, he may need time to adjust his routes to fit his new starting position.

Though his inefficient routes are not new for Collins. In 2025, he ranked 92nd out of 93 qualified outfielders in route efficiency. While his 2025 mark was not great, he was only 2.1 feet less than average last season, much less severe than his current mark. His reaction and burst distances were also slightly better in 2025 to help offset his poor route efficiency. His reaction was 4 feet above average, and his burst was 1.4 feet above average.

Lack of Conversions on Difficult Plays

Finally, Collins has yet to record a “2+ Star” out (balls with a catch probability of 90% or lower) in 2026 in nine attempts.

In 2025, Collins was able to record outs on 51.9% of difficult catches to add meaningful value in Milwaukee’s outfield. While Collins is able to catch the more probable opportunities, he has yet to make an impact in Kansas City in stopping the more difficult fly balls.

Potential Health Concerns

It is also worth noting that Collins fought a variety of injuries this offseason. He received “platelet-rich plasma injections in both of his knees” in the offseason to address tendinitis in his knees. Add that to his tightness from spring training, Collins has a variety of potentially nagging issues that could impact his fielding, despite his increased sprint speed so far. While there has not been a recent report addressing any health concerns, it is worth considering if these injuries have carried into the regular season.

Conclusion

There is a lot of time left in the season for Collins to turn the corner for his fielding run value. Getting more reps will help him continue to gain familiarity with the spacious Kauffman Stadium outfield. If he can improve his range, particularly in his route efficiency and lateral movement, his defensive value will improve, and Royals pitchers will be grateful.