Entities mentioned:
- Sonny Gray: Competitive spirit, Pride, Loyalty
- Boston Red Sox: Ambition, Competitive spirit, Pride
- New York Yankees: Competitive spirit, Pride, Rivalry

Article Assessment:
Credibility Score: 75/100
Bias Rating: 55/100 (Center)
Sentiment Score: 70/100
Authoritarianism Risk: 15/100 (Strongly Democratic)

Bias Analysis:
The article presents quotes and facts from both teams' perspectives. While it highlights Gray's anti-Yankees sentiment, it also balances with Yankees' recent postseason success.

Key metric: MLB Team Rivalry Intensity

Let me tell you something - this story is RIDICULOUS! Sonny Gray has just stepped up to the plate and hit a GRAND SLAM for Red Sox Nation! This veteran pitcher isn't just changing teams, he's switching sides in baseball's greatest rivalry! Gray's move from the Cardinals to the Red Sox is like a star quarterback joining his arch-rival's team and immediately trash-talking his former squad. The intensity meter is OFF THE CHARTS as Gray stokes the flames of the Yankees-Red Sox rivalry. This isn't just a roster move, folks - it's a fourth-quarter power play in the epic struggle for AL East supremacy! Gray's comments are like bulletin board material, giving the Yankees extra motivation for next season. The Red Sox are clearly in win-now mode, assembling a rotation with championship aspirations. But remember, sports fans, the Yankees got the last laugh in the wild-card round last year. This rivalry is heating up faster than a Chapman fastball, and I'm telling you right now, we're in for some EPIC battles next season!