It seems like there are a lot more entries in certain style categories (American Ale, Belgian and French Ale, Specialty Beer) and a lot fewer in others (Lager categories). A category with more entries should be objectively more difficult to win in than one with less, so it's something to consider if you want to compete in a category where you have decent odds.

You could add facts or opinions about why this is the case (e.g. lagers are arguably harder to brew than ales, hence less entries) but that might be too subjective.