It's not a numbers game. Every president and congress is different. Every time is different, with very different issues facing the nation at any given First 100 Days.
I agree. I can see comparing a current president's accomplishments/failures to the most recent president because the time frame is brief compared to a comparison of all presidents. But even then, things are different as Turtle correctly points out. It is, however valid to score a president's accomplishments/failures using the 100-day scorecard he himself offered up.
I grew weary of the 100 day thing weeks ago as the media continually brought it up. That standard seems to me to be arbitrary and meaningless. The 100 day thing gives lots of people lots to talk about but how important is it really?
My answer is it's not important at all. But Donald Trump's answer quite different. In fact, Trump is on record making the first 100 days of his administration something of crucial importance in evaluating the validity of his judgement, the reliability of his words and his claimed ability to get things done.
That item of record, and the scorecard Trump himself provided is the Contract With the American Voter, which he personally signed on October 22, 2016, and had posted online for the world to see then, and refer to in the future. In that contract, Trump himself vests his first 100 days in office with profound significance. These promises were not simple utterances made on the campaign trail. They were put in writing and presented as a contract under Trump's signature.
Scoring is made easy with the help of this
Trump Promise Tracker, maintained by the Washington Post. While that publication is no friend of Trump's, the promise tracker seems to be an objective tally of the promises Trump made on October 22, 2016 and the status of each with as his time in office proceeds.
Trump's first 100 days in office ends next Saturday. It appears he has a lot of work to do to fulfill his Contract with the American Voter.