If you use someone or something as a yardstick, you use them as a standard for comparison when you are judging other people or things.
①There has been no yardstick by which potential students can assess individual schools before signing up for a course.
②She had never had a real boyfriend before and so had no yardstick by which to compare Charles's behaviour.
neck and neck
In a competition, especially an election, if two or more competitors are neck and neck, they are level with each other and have an equal chance of winning.
①The latest polls indicate that the two main parties are neck and neck .
②The party is running neck-and-neck with Labour.