The theme of the Week 15 hitters and luck factors article involves several struggling hitters based on expectations. However, one hitter struggled to begin the season while performing much better lately. For these struggling hitters, it might present a buy-low opportunity via trade if we trust the track record and underlying metrics. Like usual, we'll be looking at whether to buy, sell or hold these hitters.Kyle Tucker, OF, Dodgers (99% Rostered)After changing teams for the second straight season, Kyle Tucker has been underperforming. Tucker has gone 20/25 in three of the past four seasons, with 2024 as the outlier (23/11) due to injuries. His strikeout rate is the highest since 2020, aligning with his 10.4% swinging-strike rate increasing by 1.5 points from his career average.That said, Tucker hasn't been as patient. His 24.5% chase rate is nearly two points higher than his career average. Furthermore, Tucker's chase rate was under 18% over the previous two seasons, showing he has been more aggressive this season. That aligns with Tucker's 78.3% contact rate being over three points below his career norm.Tucker's 21.9% pulled air rate dropped from 24.8% (2025) and 26.2% (2024). However, his pulled air rate is nearly identical to his career average. That's notable because Tucker has been somewhat unfortunate in his home run rate, given his 7.7% HR/F this season, down from 13.9% in his career. The Dodgers' home park ranks fifth in home run park factors for left-handed hitters across the three-year rolling averages, significantly better than the Cubs' home park (No. 14).Unfortunately, Tucker's 3.8% barrel rate per plate appearance has been cut in half this season compared to his career average (7.3%). Since he continues to pull the ball into the air, it appears that he isn't hitting the ball as hard when he elevates it. That's evident by Tucker's 90.7 mph average exit velocity on flyballs and linedrives (FB/LD), ranking 214th this season. For context, Tucker ranked 139th (93.5 mph) in 2025 and 87th (94.1 mph) in 2024 in average exit velocity on FB/LD.From a speed standpoint, Tucker's 6% stolen base opportunity rate was cut in half compared to his career average (16%). He doesn't typically flash average speed, so he tends to be smart on the basepaths. The projections have Tucker with 20 home runs, 15+ stolen bases and a .260 batting average. That's far from what fantasy managers expected.History tells us to buy low, though it's logical to be cautious with Tucker.Jazz Chisholm Jr., 2B, Yankees (99% Rostered)Don't let the in-game lollipops distract us from realizing Jazz Chisholm Jr. is ready to post a career high in stolen bases. Chisholm is on pace for 25+ home runs and 50+ stolen bases, making him a rare fantasy asset. His plate discipline has been similar to the career norms. However, Chisholm understands his home park and continues to pull the ball at a high rate. That's evidenced by Chisholm's 50.8% pull rate in 2025, increasing to 55.8% (2026).Here's a look at the Yankees 2B's flyball and pull percentages over the past three seasons.Corbin Young via FanGraphsFurthermore, Chisholm's 22.8% pulled air rate aligns closely with the 2025 numbers (24.5%). There can be diminishing returns when hitters pull the ball too often. However, it has been a concerted effort for Chisholm to pull his batted balls for home runs. Interestingly, Chisholm's 5.2% barrel rate per plate appearance fell from 9% (2025). That suggests Chisholm's power metrics support the lower home run output this season.Chisholm has a 40% stolen base opportunity rate, contributing to his spike in steals this season. He has been converting his stolen base chances into steals 86% of the time. Both metrics have been 6-9 percentage points better than his career norms. There's a good chance Chisholm builds upon his 2024 season from a power and speed perspective.When we put aside Chisholm's attitude and drama, it might present a buy-high opportunity.Michael Busch, 1B, Cubs (82% Rostered)Michael Busch has been underperforming based on expectations after hitting 34 home runs last season. Injuries haven't been an issue for Busch, so we can't blame that. He has been making a similar contact rate. However, Busch is being more patient, with his 41.2% swing rate and 61.7% zone swing rate. Both metrics have been 3-5 percentage points below his career norms.Here's a look at Busch's zone swing percentage over the past three seasons.Corbin Young via FanGraphsAs a left-handed hitter, Busch pulled the ball 46.8% of the time last season. That dropped to 36.5% this season, aligning with his 15.7% pulled air rate. For context, Busch's pulled air rate dropped from over 20% in the previous two seasons. That aligns with his 6.7% barrel rate per plate appearance, falling from 11.1% (2025) and 8.2% (career).Busch has been hitting the ball and swinging the bat hard when he pulls them into the air. However, his 25% barrel rate per plate appearance on pulled balls into the air, dipping significantly from 38.1% (2025) and 32.4% (2024) might make us skeptical on whether his home run output returns. It could hint at the ball not traveling as far this season. Unfortunately, the rest of the season projections indicate 20+ home runs instead of 30+.Busch's 2025 season might be the outlier, so a repeat of 2024 feels probable. That said, it will lead fantasy managers to adjust expectations based on the underlying metrics. It's unfair to buy low on Busch, expecting the 2025 power numbers. However, he is a strong asset in points and OBP leagues with a 15.5% walk rate and a .368 OBP this season.Alex Bregman, 3B, Cubs (89% Rostered)There have been mentions of Alex Bregman struggling with his swing this season. Like Tucker, Bregman joined a new team for his second consecutive season. After three straight seasons with 20+ home runs in Houston, his home run total fell below 20 with the Red Sox, though a strained quad impacted last season's volume.Bregman's plate discipline looks similar, with a contact and chase rate within 2-3 percentage points. He uses the pull-heavy approach (48.4%) with a 23.8% pulled-air rate. Bregman has been unfortunate from a home run standpoint (6.4% HR/F), which would be a career low that's five points below his career average.He never had high-end exit velocity numbers, though his 3.3% barrel rate per plate appearance this season is over 1.5 points below the league average. That aligns with Bregman's 94.5 mph (No. 108) average exit velocity on flyballs and line drives from 2025, dropping to 91.4 mph (No. 186) this season. Bregman has been struggling to barrel up the ball and hit the ball hard when he elevates it.The Cubs' home park has been closer to league average (101) in the three-year rolling Statcast Park Factors to right-handed hitters. That's better than the Red Sox home park (90 Park Factor, No. 22). Maybe Bregman lucks into a few additional home runs as the season progresses, but that's tricky when the exit velocity data doesn't support those expectations.The projections expect Bregman to hit 15-16 home runs with a .240 to .250 batting average. When we toss out the name value, that's a league-average hitter who can be streamed off waivers. Nothing to do other than hold Bregman, but it doesn't look like he should be a buy-low candidate.Jac Caglianone, 1B/OF, Royals (79% Rostered)Before the middle of May, Jac Caglianone wasn't meeting expectations. He had four home runs and a .238 batting average through May 15. Caglianone was hitting the ball hard earlier in the season, with a 16.1% barrel rate and a .243 xBA. Since May 16, Caglianone has 10 home runs, three stolen bases and a .288 batting average. The underlying metrics have been strong, given his 16.3% barrel rate and a .316 xBA since May 16.Here's a look at Caglianone's xwOBA over the past two seasons.Corbin Young via Baseball SavantAfter a .172 BABIP last season, Caglianone's .345 BABIP is fueling a significantly better batting average (.264) this season. In the minors, Caglianone has shown higher BABIPs, so maybe that's something we should expect more often. He has been making less contact (71.9%) this season after a 75% contact rate last year. Caglianone's swinging-strike rate increased by one percentage point with his strikeout rate above 30%. Thankfully, Caglianone possesses elite power.Caglianone has the seventh-highest bat speed (77.1 mph), second-best EV50 and a 9.8% barrel rate per plate appearance (No. 19). That type of power is similar to Nick Kurtz and Oneil Cruz. Hitters with this type of power skills, like Caglianone, can have a higher HR/F (23.7%). So, don't expect Caglianone's home run rates to regress with his elite power and barrel rates.The projections expect Caglianone to hit 25+ home runs, which should be the floor, with 40 being probable at some point in his career. This is what trusting a player's skills can look like when the outcomes regress toward the expected metrics.