Hi,
Someone saying that the Yankees are the best baseball team in history is opinion, not fact. I'm sure many people would disagree with that.
Another opinionated statement is saying that they pay their players too much, as some people may think they may not be paid enough, or that they are paid fairly.
Lastly, the final opinionated statement is saying they always have a great outfield. You can't guarantee that they will always have a great outfield, as some may disagree.
However, saying they sell hot dogs is fact. Someone can't walk up and say 'They don't sell hot dogs', straight in front of a hot dog stand in Yankee Stadium. You can't just say 'They don't sell hot dogs, that's just your opinion'.
Hopefully, this helps.