It's rather historic
What does the MLB 150 Patch stand for?
With the new baseball season underway you may have noticed a new patch — MLB 150 — which appears on the cap and right jersey sleeve of MLB clubs. The patch will be worn throughout the season and celebrates the 150th anniversary of the first openly all-salaried professional baseball team — the 1869 Cincinnati Red Stockings. This isn't the first time Major League Baseball has celebrated an anniversary. In 1969, the league marked its 100th anniversary and in 1994 celebrated its 125th. This will, however, be the first time an MLB league-wide anniversary recognition will be featured on caps.
Since the anniversary is so tied to the Reds, the team will have its own unique 150th patch.
In addition, MLB will support Cincinnati Reds activities and promotions as the club celebrates the anniversary with 15 throwback uniforms worn throughout the season and a special commemorative logo that they will wear on caps (see above) and jerseys in lieu of the normal MLB 150 patch.
Perhaps the anniversary will lead to the Reds having a good season, considering the 1869 Cincinnati Red Stockings recorded a perfect 57-0 record. No pressure.