The Chaim Bloom era in Boston came to an end on Thursday when the Red Sox announced they parted ways with their Chief Baseball Officer.

Bloom took over from Dave Dombrowski going into the 2020 season. His four seasons in charge included one playoff appearance and at least two losing seasons. The Red Sox are flirting with adding another losing season to that tally this year and hopes of making the playoffs are low sitting 7.5 games out as of Sept. 14.

So where do Bloom go wrong?

No. 3 Chaim Bloom mistake with the Red Sox: The MLB trade deadline

The MLB trade deadline is all about making a decision, one way or another. Teams that waffle at the deadline rarely find success. Going all in on being a buyer may not work out, but it certainly gives you a better chance than sitting in the middle and letting everyone else make moves.

That's where Bloom has gone wrong, particularly in 2023.

The Red Sox were on a hot streak in July with a 15-8 record in the month, but they were still nine games out of first and 1.5 games out of the wild card. So they either needed to pick up some pitching to truly go for it. Or they needed to cash in on trade assets like James Paxton, Justin Turner, Adam Duvall and others.

Bloom did neither. Boston was stuck in the middle and inevitably floundered while wasting their opportunity to set up for the future.

That was a theme for Bloom...

No. 2 Chaim Bloom mistake with the Red Sox: Letting Xander Bogaerts leave in free agency

The 2023 trade deadline wasn't anything new for Chaim Bloom. He made similar mistakes in 2022, the most costly of which involved Xander Bogaerts. The Red Sox probably should have just embraced a sellers mentality but they half-heartedly called themselves buyers by picking up a few players who did little to prevent a fifth-place finish.

Meanwhile, Bogaerts sped towards free agency with the Red Sox making laughable attempts to re-sign him while prioritizing a Rafael Devers extension. Bogaerts, who had signaled all along he wanted to stay in Boston, ended up leaving for the Padres.

Yes, locking in Devers to a long-term deal was a win for Bloom but the third baseman can't do it alone. If signing Bogaerts wasn't a priority, the Red Sox failure to trade him at the deadline was a massive miscue.

Part of leading a front office is understanding what ownership will and won't let you do and working around it. If the money wasn't going to be there for Devers and Bogaerts, the latter needed to be traded. Bloom let him walk for nothing.

But that's still not the biggest Bloom mistake...

No. 1 Chaim Bloom mistake with the Red Sox: The Mookie Betts trade

The Mookie Betts trade will go down as one of the biggest fleecings in MLB history. To acquire a future Hall of Famer at 26 years old with an MVP under his belt already, the Dodgers gave up Alex Verdugo Connor Wong and Jeter Downs.

At the time, Verdugo was the No. 35 prospect in baseball and LA's top prospect. Downs was No. 44 and Wong wasn't in the Top 100, ranking No. 28 in the LA farm system.

Verdugo has been a serviceable player for the Red Sox but nothing remotely as special as Betts. The additions of Wong and Downs were useless. The fact that the former has a place in the lineup for the Red Sox in 2023 is an indictment of the front office.

Being unable to hold on to Betts isn't on Bloom. If the owners weren't willing to pay him the contract he was owed, trading him was better than letting him walk (like they'd do for Bogaerts a couple of years later). But getting such a paltry return for a player of Betts category defied belief, then and now. And the deal has only looked worse and worse each year.

When it comes down to it, Blooms legacy is the Mookie Betts trade. It's not a good one.