The Major League Baseball (MLB) saw its payroll number for the 2021 season drop by 4 percent to $4.05 billion, the lowest level for a fully completed season since 2015, according to the Associated Press.

Six years ago, the total salary number of the majors league was $3.9 billion and then continued to grow in the following two years before reaching historic high of $4.25 billion in 2017. That was also the first year since the current collective bargaining agreement (CBA) was signed.

Though it lowered down a bit in 2018 and 2019, the total number was never below $4.2 billion. The 2020 season was a shortened one due to COVID-19 and had only 60 games in the regular season, so it's an acceptable exception. However, in the first full season after that, the payroll continuing to drop became one of the major reasons behind the lockdown between team owners and players.

During last month's CBA negotiation, players proposed to lift the luxury tax line of $210 million to $245 million as a way to stimulate spending. 

In the past season, only two teams paid luxury tax. The Los Angeles Dodgers, which won the World Series title in 2020, saw their total salary rise to $262 million, the second highest in league history, following the $291 million of the same franchise in 2015.

As a result, the Dodgers paid $32.65 million of tax, only to end up losing to the Atlanta Braves in the National League Championship Series (NLCS).

The San Diego Padres were the other team that paid luxury tax of $1.29 million. However, they failed to even reach the playoffs after burning tons of money on Fernando Tatis Jr., Manny Machado, Yu Darvish, Wil Myers and Eric Hosmer.

Meanwhile, the five teams that were less than $4 million away from the luxury line finished their season in different ways. The Philadelphia Phillies ($209.4 million) failed to make the playoffs. So did the New York Mets ($207.7 million). The New York Yankees ($208.4 million) lost to be Boston Red Sox ($207.6 million) in the NL Wild Card Game. The Red Sox then were eliminated by the Tampa Bay Rays NL Division Series. The Houston Astros ($206.6 million) reached the World Series but lost to the Braves in the end.

Surprisingly, the Braves, with only a payroll of $148 million, won the World Series title in the end. There were also 10 teams in the majors league that spent less than $100 million. The bottom five were the Pittsburgh Pirates ($50 million), Cleveland Guardians ($53 million), Baltimore Orioles ($59 million), Miami Marlins ($61 million) and Rays ($77 million).

That's partly why teams offered only to lift the luxury line to $214 million, instead of $245 million that players wanted. The difference of $31 million is basically the number of an annual salary of a maximum contract.

There are a series of differences between teams and players but most of them are related to money, just like the payroll.