Here is a big difference. This is Hiura's heat map against fastball offerings when he is behind in the count. 2019 is the first link, 2021 is the second link. When ahead in the count pitchers like to throw fastballs down and away at an incredibly high percentage. 2019 https://www.fangraphs.com/players/keston-hiura/20003/heat-maps?position=2B&ss=&se=&type=0&hand=all&count=behind&blur=1&grid=10&view=bat&pitch=CU,FA,FC,FS&season=2019&data=pi 2021 https://www.fangraphs.com/players/keston-hiura/20003/heat-maps?position=2B&ss=&se=&type=0&hand=all&count=behind&blur=1&grid=10&view=bat&pitch=CU,FA,FC,FS&season=2021&data=pi You could play around with these heat maps endlessly and in my opinion this is really describes why he is struggling. He can't hit fastballs high and he can't hit them low and away. This goes for off speed stuff too. His average and ability to make contact in these areas is pretty bad. Ironically these two areas are also where most of his power output comes from, that is probably why he still showed power in 2020 even though he sucked quite a bit. Great success when he puts high and low away fastballs in play...but also the biggest areas he can't make contact. Not a good combination to have if you want success. Career Contact % https://www.fangraphs.com/players/keston-hiura/20003/heat-maps?position=2B&ss=&se=&hand=all&count=all&pitch=&season=all&view=bat&data=&grid=10&blur=1&type=3 Career ISO on Balls in Play https://www.fangraphs.com/players/keston-hiura/20003/heat-maps?position=2B&ss=&se=&hand=all&count=all&pitch=&season=all&view=bat&data=&grid=10&blur=1&type=11 The high fastball is just crippling for the guy though. 55% contact rate at the top of the strike zone and about 35% just above the strike zone for 2019. In 2021 he has a contact rate between 5%-25% just inside the top of the strike zone and 0% just above the strike zone. 2020 was somewhat in between the two...so this has declined every year of his career. They have to find a way for him to hit high fastballs. Until then, nothing will matter. When scrub pitchers are making you whiff on high fastballs like it is coming in at 110mph you will not find success. Pitchers have learned him and are pitching him differently. He needs to adjust or he will never improve.