Per Fox Sports Kansas City Press Release:
Thursday’s opening day game was the highest-rated Royals season or home opener broadcast on FOX Sports Kansas City. The Angels-Royals telecast generated a 5.4 household rating in the Kansas City DMA, according to Nielsen Media Research.
The previous high rating for a Royals opener came last year, a 5.3 for the Royals April 5, 2010 loss to Detroit.
Of course, FSKC has only done Royals games for ten years. I'd be curious to know what some of the ratings were back in the glory days. You would think that fewer channels+ better teams would mean more viewers, but it doesn't always work like that. Interest in sports isn't static, and if anything, appears to be growing, or at least becoming a more intense animal.